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April 16, 2014

Search: An odds ratio of 1.2 (95% confidence interval: 0.8-1.5) is found for the association of low socioeconomic status

Number of results: 29,304

STATISTICS
A study examining the relationship between fetal X-ray exposure and a particular type of childhood blood cancer found the following odds ratio (and 95% confidence interval) for the association: 2.44 (0.95 to 6.33). This result would likely be considered: A) clinically ...
Tuesday, August 6, 2013 at 3:54pm by Susie

STATISTICS
A study examining the relationship between fetal X-ray exposure and a particular type of childhood blood cancer found the following odds ratio (and 95% confidence interval) for the association: 2.44 (0.95 to 6.33). This result would likely be considered: clinically significant...
Wednesday, August 7, 2013 at 5:46am by Susie

STATISTICS
A study examining the relationship between fetal X-ray exposure and a particular type of childhood blood cancer found the following odds ratio (and 95% confidence interval) for the association: 2.44 (0.95 to 6.33). This result would likely be considered: a. clinically ...
Saturday, August 10, 2013 at 7:12pm by smoothjive

stats
The following data were collected from a case-control study of breast cancer and fat intake: case control High-fat diet 10 5 Low-fat diet 40 55 50 60 Statistical inferences for odds ratios are based on the natural log of the odds ratio, rather than the odds ratio itself (...
Tuesday, July 16, 2013 at 2:38am by thane

Statistics
Which of the following statements best describes the uncertainty associated with a 95% confidence interval for a population proportion, computed from a simple random sample? A. We don't know whether the particular confidence interval is successful or not, but 95% of ...
Friday, May 18, 2012 at 5:02pm by Mary

Statistics
Multiple Choice Which of the following statements is true about the 95% confidence interval of the average of a sample? A) 95 of 100 avgs of samples will be within the limits of the confidence interval. B) There is a 95% chance the avg of the population to be within the limits...
Friday, July 26, 2013 at 6:00am by Andrew

RES 341
A sample of 300 is taken and the sample mean is computed to be 7.65 and the sample standard deviation is 5. Assume the data is ratio level. Compute the 95% confidence interval on the mean. Compute the 3.9% confidence interval on the mean Which confidence interval is more ...
Saturday, October 16, 2010 at 12:15pm by Meh

Statistics
What is meant by the 95% confidence interval of the mean ? That 95% of my sample is OK to do more tests. That I am 95% confident that the confidence interval will contain the parameter being estimated. That 5% of my sample is not OK. That I am 95% sure that the population mean...
Tuesday, June 22, 2010 at 10:47am by Jacob

statistics
What is meant by the 95% confidence interval of the mean ? That 95% of my sample is OK to do more tests. That I am 95% confident that the confidence interval will contain the parameter being estimated. That 5% of my sample is not OK. That I am 95% sure that the population mean...
Tuesday, August 17, 2010 at 2:29pm by Karen

Statistics
1. A certain population follows a normal distribution, with mean m and standard deviation s = 2.5. You collect data and test the hypotheses H0: m = 1, Ha: m 1. You obtain a P-value of 0.022. Which of the following is true? Why? a. A 95% confidence interval for m will include ...
Saturday, November 29, 2008 at 8:32am by Latoya

Epidemiology
Consider each of the following scenarios and explain whether the variable in question is a confounder: a. A study of the relationship between exercise and heart attacks that is conducted among women who do not smoke. Explain whether gender is a confounder. b. A case-control...
Sunday, October 17, 2010 at 5:06pm by Joe

math
The new Twinkle bulb is being developed to last more than 1000 hours. A random sample of 100 of these new bulbs is selected from the production line. It was found that 48 lasted more than 1000 hours. Find the point estimate for the population proportion, the margin of error ...
Sunday, April 17, 2011 at 4:18pm by Heaven

Statistics
Which of the following statements correctly interprets a 95% confidence interval on a population mean? a. It is a single point estimate b. Used to quantify the certainty of the sample standard deviation c. A 99% confidence interval is narrower than the 95% confidence interval ...
Wednesday, September 15, 2010 at 9:18am by Beata Chmielewska

Statistics
I'll give you a hint to help you make the selection: A 95% confidence interval means that there is a 95% probability that the true population proportion lies within the confidence interval.
Friday, May 18, 2012 at 5:02pm by MathGuru

UOP
5) In a 95% Confidence Interval, the true mean has what chance of falling between the Lower Limit and Upper Limits of the calculated confidence interval? A. .90 B. 95% C. .05 D. 5%
Saturday, April 13, 2013 at 2:40pm by Linda

Environmental Management
A. The 95% confidence interval is: (a) Larger than the 99% confidence interval (b) Smaller than the 99% confidence interval (c) The same as the 99% confidence interval
Monday, July 13, 2009 at 2:35pm by Jox

statistics
Refer to Table 1 in the article Snail Shells in a Practical Application of Statistical Procedures in the Electronic Reserve Readings. Find the margin of error, E, with a confidence interval of your choosing (50-99%). What is the significance of choosing a confidence interval...
Thursday, April 26, 2012 at 3:37pm by len

statistics
Consider a 95% confidence interval for a population mean constructed from a random sample of 250 observations taken from a Normal population. Sigma is known to be 14. If we were to construct another 95% confidence interval, this time using 1,000 observations, how would the ...
Sunday, February 20, 2011 at 7:02pm by AMY

statistics
Consider a 95% confidence interval for a population mean constructed from a random sample of 250 observations taken from a Normal population. Sigma is known to be 14. If we were to construct another 95% confidence interval, this time using 1,000 observations, how would the ...
Sunday, February 20, 2011 at 7:02pm by AMY

statistics
95% confidence interval indicates that you have 5% outside the confidence interval and 2.5% on either side. This is an area of .025. You can use a calculator or a t-table to find the critical value. Multiply that value times the standard deviation. add this value to the mean ...
Wednesday, February 13, 2013 at 1:08pm by JJ

Statistics
The standard deviation for a population is σ = 15.3. A sample of 36 observations selected from this population gave a mean equal to 74.8. a) Make a 90% confidence interval for μ b) Construct a 95% confidence interval for μ. c) Determine a 99% confidence interval...
Thursday, November 21, 2013 at 11:11am by ----

Statistics
The 95% confidence interval is: (a) Larger than the 99% confidence interval (b) Smaller than the 99% confidence interval (c) The same as the 99% confidence interval
Sunday, October 28, 2007 at 8:18am by Thano

Statistics
We have calculated a 95% confidence interval for a proportion and would prefer the confidence interval to be more precise, that is narrower. Using the same sample, we can narrow the confidence interval using which of the following? A) increasing the confidence level B) ...
Sunday, October 27, 2013 at 9:07am by Nick

Statistics
If a 90%, 95% and 99% confidence interval are found for a population mean, how are the three interval estimates related to each other?
Sunday, December 7, 2008 at 7:26pm by Cecilia

Statistics
95% confidence interval is approximately 2 standard deviations (SDs) away from the mean in each direction (}2 SD). Do you still believe that the 95% confidence interval would be larger for a smaller SD? I hope this helps. Thanks for asking.
Sunday, October 28, 2007 at 8:18am by PsyDAG

epidemiology
Assessing Random Error, Confounding, and Effect Modification Although researchers do their best to reduce error within every study, there will always be error. It is important to identify and report any possible error within the research study in order to accurately interpret ...
Sunday, October 10, 2010 at 6:26am by Roxana

statistics
The Frayed Nerves Anxiety Scale (FNAS) is used to measure the anxiety level of people on a scale from 0 to 1000. Four students were randomly chosen and given the FNAS before their second exam. Their scores were 700, 653, 740, and 707. The standard deviation sigma of the test ...
Monday, October 17, 2011 at 7:10pm by Anand

Statistics
Find a confidence interval formula using proportions. Convert your proportions to decimals for ease in calculation. Use + or - 1.96 for the interval in the formula to represent 95 percent confidence (this is found using a z-table). You should be able to draw your conclusions ...
Monday, August 31, 2009 at 6:59pm by MathGuru

Statistics
When consumers apply for credit, their credit is rated using the FICO score. A bank manager used a random sample of the credit scores of 18 customers and determined the following 95% confidence interval: (613.6, 708.0) If the sample used 45 customers rather than 18 customers, ...
Wednesday, November 6, 2013 at 7:51pm by Katelyn

statistics
What do confidence intervals represent? What is the most controllable method of increasing the precision of or narrowing the confidence interval? What percentage of times will the mean, or population proportion, not be found within the confidence interval?
Friday, April 30, 2010 at 7:04pm by Amy

Statistics
A simple random sample of 50 female 14-year-olds is selected. The sample mean height of the girls is found to be 62 inches. Assume the height of 14-year-old girls is normally distributed with a standard deviation of 5 inches. 1. Based on these data, a 95% confidence interval ...
Tuesday, November 27, 2012 at 1:45am by Clay

Statistics
A random sample of 90 observations produced a mean that = 25.9 and a standard deviation s =2.4 (a)Find a 95% confidence interval for u (b)Find a 90% confidence interval for u (c)Find a 99% confidence interval for u (Use integers or decimals for any number in the expression. ...
Sunday, March 23, 2014 at 9:30am by Carol Harper

statistics
Use a proportional confidence interval formula: CI95 = p + or - (1.96)(0.015) ...where p = x/n Note: + or - 1.96 represents 95% confidence interval. For p in your problem: 40/400 = .1 I let you take it from here to calculate the interval.
Friday, May 18, 2012 at 10:19pm by MathGuru

Statistics:Significance Test and Confidence Interv
Significance Test and Confidence Intervals In General: The article contains a 95% confidence interval. Would the margin of error in a 99% confidence interval computed from the same data be less, the same, or greater?
Tuesday, September 11, 2007 at 4:30pm by Carma

Statistics
1. A study of 40 people found that they could do on the average15 pull ups with a standard deviation of .6. Find the 99% confidence interval for the mean of the population. 2. A study of 50 pizza delivery workers found that they could make 6 deliveries per hour with a standard...
Friday, May 3, 2013 at 11:45am by Cam

statistics
Use confidence interval formulas to construct the interval for . CI95 = mean + or - 1.96 (sd/√n) ...where + or - 1.96 represents the 95% interval using a z-distribution, sd = standard deviation, and n = sample size. Confidence interval using a t-distribution would be ...
Thursday, October 15, 2009 at 10:15am by MathGuru

Statistics
Hoping to lure more shoppers downtown, a city builds a new parking garage in the central business district. The city hopes that the parking revenues will pay for the garage. During a recent two month period (44 days), the city statistician calculated the 95% confidence ...
Sunday, November 10, 2013 at 6:32pm by Katie

Statistics
Suppose x has a mound-shaped distribution with sigma = 9 . A random sample of size 36 has sample mean 20. Is it appropriate to use a normal distribution to compute a confidence interval for the population mean m? Explain. Find a 95% confidence interval for m. Explain the ...
Saturday, April 27, 2013 at 6:54pm by Steph

college stats
Sorry for all the questions, I really need help and an explanation so I can fully understand. I really appreciate everything. Thank you. In a random sample of 519 judges, it was found that 285 had an introvert personality type. Construct a 95% confidence interval for the ...
Friday, July 12, 2013 at 6:21pm by penelope

statistics
Use a proportional confidence interval formula: CI95 = p + or - (1.96)(√pq/n) Note: + or - 1.96 represents 95% confidence interval. For p in your problem: .42 For q: 1 - p = 1 - .42 = .58 n = 1500 I let you take it from here to calculate the interval.
Monday, March 25, 2013 at 10:46pm by MathGuru

STATISTICS
In a cross-sectional study of heart disease and gender in middle-aged men and women, 10% of men in the sample had prevalent heart disease compared with only 5% of women in the sample. After adjusting for age in multivariate logistic regression, the odds ratio for heart disease...
Tuesday, August 6, 2013 at 3:44pm by Susie

statistics
Pleas HeLp!!!!!!!!!! A random sample of the test scores of 100 applicants for college entry at a large junior college showed a mean score of 72.6. Determine a 99%, 95%, and 90% confidence interval for the m mean score of all applicants at the junior college. Assume the ...
Saturday, September 17, 2011 at 10:00pm by courntey

Math
Suppose a population is sampled and the sample mean is 16.8. The sample standard deviation is 6.0 I am to assume the sample is larger than 30) and the sample size is 65. How do I calculate 95% and 98% confidence intervals. State which interval wider and why please. How would I...
Wednesday, February 13, 2013 at 10:58pm by Mandi

Statistics
The point estimate is an estimate of the population percentage given the sample you are working with. Percentage = 96/240 = p-hat q-hat = 1 - p-hat 97% confidence interval means that you have 3% left which is split between two tails. You need to split .03 in half to get .015. ...
Sunday, March 10, 2013 at 5:12pm by Dr. Jane

stats
In a poll of 100 adults, 45% reported they believed in faith healing. (USA Today, 20 April 1998). Based on this survey, a 95% confidence interval for the proportion in the population who believe in faith healing is about 42% to 48%. If this poll had been based instead on ...
Wednesday, June 23, 2010 at 5:27pm by Anonymous

statistical applications
In the media, numerous surveys are often displayed reporting percentages or proportions. A margin of error is often reported in the survey and this is used to calculate confidence intervals. Why is it important to create/report confidence intervals (CI) rather than just ...
Friday, May 28, 2010 at 9:21am by cortez

QNT351
use a 95% confidence interval to estimate the difference between the population means. Interpret the confidence interval. random sample 390 x1 5258 s1 152 x2 5220 s2 192
Thursday, September 27, 2012 at 6:40pm by Terri

Math
5. The following random sample was selected : 4, 6, 3, 5, 9, 3. Find the 95% confidence interval for the mean of the population. 6. In a sample of 35 high school seniors, 14 of them are attending college in the fall. Find the 95% confidence interval for the true proportion of ...
Thursday, May 9, 2013 at 1:17pm by Anonymous

statistic
1. Past experience indicates that the variance, 2x, of the scores, X, obtained on the verbal portion of a test is 5,625. Similarly, the variance 2y, of the scores, Y, on the mathematical portion is 2,500. (a) A random sample of size n = 64 yields a sample mean verbal score...
Sunday, January 30, 2011 at 12:45am by Tian

statistics
Use a proportional confidence interval formula: CI95 = p + or - (1.96)(√pq/n) Note: + or - 1.96 represents 95% confidence interval. For p in your problem: 520/1000 = .52 For q: 1 - p = 1 - .52 = .48 n = 1000 I let you take it from here to calculate the interval.
Wednesday, May 1, 2013 at 9:54am by MathGuru

statistics
Use a proportional confidence interval formula: CI95 = p + or - (1.96)(√pq/n) Note: + or - 1.96 represents 95% confidence interval. For p in your problem: 6062/12000 = 0.505 For q: 1 - p = 1 - 0.505 = 0.495 n = 12000 I let you take it from here to calculate the interval.
Sunday, June 23, 2013 at 5:01pm by MathGuru

Statistics
A survey organization takes a simple random sample of 625 households from a city of 80,000 households. On the average, there are 2.30 persons per sample household, and the SD is 1.75. Say whether each of the following statements are True or false and explain (a) The SE for the...
Wednesday, October 26, 2011 at 12:34pm by Joyann

Statistics
1. A study of 40 people found that they could do on the average15 pull ups with a standard deviation of .6. Find the 99% confidence interval for the mean of the population. 2. A study of 50 pizza delivery workers found that they could make 6 deliveries per hour with a standard...
Thursday, May 9, 2013 at 1:16pm by Anonymous

statistics
Example of a proportional confidence interval formula: CI95 = p (1.96)[√(pq/n)] ...where p = x/n, q = 1 - p, and n = sample size. Note: 1.96 represents 95% confidence interval. For p in your problem: 350/757 = .46 For q: 1 - p = 1 - .46 = .54 n = 757 I let you take ...
Wednesday, June 13, 2012 at 6:51pm by MathGuru

Statistics
Example of a proportional confidence interval formula: CI95 = p + or - (1.96)[√(pq/n)] ...where p = x/n, q = 1 - p, and n = sample size. Note: + or - 1.96 represents 95% confidence interval. For p in your problem: 40/90 = 0.44 For q: 1 - p = 1 - 0.44 = 0.56 n = 90 I let ...
Monday, June 17, 2013 at 2:01pm by MathGuru

Statistics
These are the only ones that I am having problems with. Please help.. 8.You are given the sample mean and the sample standard deviation. Use this information to construct the 90% and the 95% confidence intervals for the population mean. Interpret the results and compare the ...
Sunday, February 17, 2013 at 7:05pm by Katie

STATISTICS
Bacterial samples were taken from several surfaces in a daycare and incubated in petri dishes. After that the number of bateria colonies were counted, with the following results 412, 437, 425, 476, 451, 483. 1) construct a 95% confidence interval for the mean number of ...
Thursday, October 11, 2007 at 7:26pm by Keirson

Math
A random survey of 500 households determines that 20% of the households would do so and that each participating household expects to recycle about 100 cans monthly with a standard deviation of 30 cans. Question (a) What is the 95% confidence interval regarding the percentage ...
Wednesday, April 21, 2010 at 10:00pm by Jamie

Statistics
Find the minimum sample size that should be chosen to assure that the proportion estimate p will be within the required margin of error, .06. Use a 95% confidence interval and a population proportion of .7. The critical value for a 95% confidence level is 1.96
Monday, June 6, 2011 at 11:12am by Eric

Stats
2) Find the minimum sample size that should be chosen to assure that the proportion estimate p will be within the required margin of error, .06. Use a 95% confidence interval and a population proportion of .7. The critical value for a 95% confidence level is 1.96
Tuesday, June 14, 2011 at 11:57am by Eric

statistics
The new Twinkle bulb is being developed to last more than 1000 hours. A random sample of 100 of these new bulbs is selected from the production line. It was found that 48 lasted more than 1000 hours. Find the point estimate for the population proportion, the margin of error ...
Tuesday, April 6, 2010 at 4:27pm by looking for someone to varify my work please

statistics
A consumer magazine has contacted a simple random sample of 33 owners of a certain model of automobile and asked each owner how many defects had to be corrected with in the first 2 months of ownership. The average number of defects was x with (with line over the x)=3.7, with a...
Thursday, October 15, 2009 at 10:15am by Tammy

Statistics Question (Confidence Interval)
A sample of 15 recent college graduates found that starting salaries for attorneys in New York City had a mean of $102,342 and a standard deviation of $21,756. Construct a 95% confidence interval for the average starting salary of all attorneys in the city. A. (89869.82, ...
Wednesday, March 14, 2012 at 11:15am by Mark

Statistics
If someone gives you a sample mean and a standard deviation, you can find a confidence interval. But what if someone gives you the confidence interval instead and asks you to find the sample mean? How can you do that? Here's an example: a 95% confidence interval for a mean is ...
Tuesday, October 4, 2011 at 7:30pm by Hope

statistics
Use a proportional confidence interval formula: CI95 = p + or - (1.96)(√pq/n) Note: + or - 1.96 represents 95% confidence interval. For p in your problem: 442/1004 For q: 1 - p n = 1004 Be sure to convert all fractions to decimals. It's easier to work with decimals in ...
Monday, March 25, 2013 at 10:24pm by MathGuru

statistics
In a sample of 100 steel wires the average breaking strength is 50 kN, with a standard deviation of 2 kN. a. Find a 95% confidence interval for the mean breaking strength of this type of wire. b. An engineer claims that the mean breaking strength is between 49.7 kN and 50.3 ...
Saturday, October 29, 2011 at 2:18pm by Don't get it!! :(

Statistics
Please help!! I have no idea how to do this question. 14. A sample of 40 CDs from your collection showed a mean length of 52.74 minutes with a standard deviation of 13.21 minutes a. Construct the 95 percent confidence interval for the mean. b. Construct the 95 percent ...
Monday, October 31, 2011 at 1:54pm by Kristi

Statistics
Professor York randomly surveyed 240 students at Oxnard University, and found that 150 of the students surveyed watch more than 10 hours of television weekly. Develop a 95% confidence interval to estimate the true proportion of students who watch more than 10 hours of ...
Monday, April 7, 2014 at 6:54pm by Angela

statistics please
a basketball scout randomly selected 144 players and timed howlong eah player took to perform a certain drill. the times in thissample were distributed with a mean of 8 minutes. the populationstandard deviation was known to be 3 minutes. (a) find the critical value for a 95% ...
Saturday, December 15, 2012 at 4:01pm by gina

statistics
1. A random sample of size 49 is taken from a large population, measuring the time it takes to complete a drivers license examination. The sample mean was found to be 47 minutes, and the sample standard deviation 5.89 minutes. Construct a 95% confidence interval around the ...
Saturday, July 17, 2010 at 11:50am by Anonymous

Math-Stat Help
In a random sample of 78 teenagers, 32 admit to texting while driving. Construct a 98% confidence interval for the percentage of teenager that text while driving. Start by showing that conditions for constructing a confidence interval are met. 1) Check conditions 2) confidence...
Thursday, April 11, 2013 at 11:41am by MELISSA

statistics
According to the Journal of the American Medical Association, the doctors found that in the week before and the week after Thanksgiving, there were 12,000 total deaths and 6062 of them occurred in the week before Thanksgiving. Construct a 95% confidence interval of the ...
Sunday, June 23, 2013 at 5:01pm by Jerome

stats
In order to make sure that their bags of chips are of sufficient weight, the Chipper Chip Company try to fill their 200 gram bags of chips with more than 203 grams. You have been given the task of investigating what proportion of bags produced do have over 203 grams of chips ...
Saturday, October 30, 2010 at 11:27pm by lollzzz

statistics
A confidence interval for the mean is a range lower < <upper where the lower bound is the smallest value of that we expect and the upper bound is the largest value of that we expect(Doane-Seward,2007). If we wanted a narrower interval(i.e. more precision) we ...
Friday, April 30, 2010 at 7:04pm by Natasha

statistics
A simple random sample of 60 items resulted in a sample mean of 80. The population standard deviation is 15. a) Compute the 95 % confidence interval for the population mean. b) Assume that the same sample mean was obtained from a sample of 120 items. Provide a 95% confidence ...
Thursday, April 7, 2011 at 5:35pm by TIMBERLY

statistics
An experimental egg farm is raising chickens to produce low cholesterol eggs. A lab tested 12 randomly selected eggs and found that the mean amount of cholesterol was x = 186 mg. The sample standard deviation was found to be s = 19.0 mg on this group. Assume that the ...
Tuesday, April 6, 2010 at 4:26pm by looking for someone to varify my work please

statistics
The population standard deviation (σ) for a standardized achievement test that is normally distributed is 8. a.) Calculate the standard error of the mean if you draw a random sample of50 test scores. Show your work for full credit . . . b.) Your sample mean is ...
Tuesday, February 21, 2012 at 4:28pm by PK

statistics
A school psychologist is trying to determine the lower boundary of a confidence interval for a IQ measure that has a mean of 100 and a standard deviation of 30 and a sample size of 100. What is the lower boundary if she was to create a 95% confidence interval?
Friday, July 1, 2011 at 5:22pm by Haywood

Statistics-Confidence Interval
Apparently Sharon has more data than is indicated on your post. Also I don't know how she found the SD. 95% = mean 1.96 SD
Monday, January 16, 2012 at 7:33pm by PsyDAG

statistics
A random sample of size 49 is taken from a large population, measuring the time it takes to complete a drivers license examination. The sample mean was found to be 47 minutes, and the sample standard deviation 5.89 minutes. Construct a 95% confidence interval around the ...
Saturday, July 17, 2010 at 4:58pm by Anonymous

Statistics
You'll need to start by finding a 95% confidence interval for 2 samples. If you use a z-table, then here is an example of a formula: CI95 = (x1 - x2) 1.96 [√(s1^2/n1 + s2^2/n2)] ...where x1, x2 are the means; 1.96 represents the 95% confidence interval using a z-...
Monday, June 18, 2012 at 10:55pm by MathGuru

Statistics
In a study to estimate a population mean, i start with a sample size 10 and calculate the 95% confidence interval. Suppose i am not satisfied with the size of the confidence interval and want to reduce it by half. Give an estimate of sample size that i need.
Monday, August 23, 2010 at 6:18pm by Zodra

math
With a confidence level of .95 and a confident interval of 5 and a population of 20,000 what is the sample size? With a confidence level of .99 and a confident interval of 5 and a population of 20,000 what is the sample size? Finally, using the sample size for question 1 and 2...
Monday, October 15, 2007 at 5:59pm by sam

Math
What effect will an outlier have on a confidence interval that is based on a small sample size? A) The interval will be smaller than an interval without the outlier. B) The interval will be the same with or without the outlier. C) The confidence interval will be wider than an ...
Saturday, November 28, 2009 at 10:58am by Jennifer

chemistry
The aspirin content in the analgesic tablets is determined from 120 samples to have a ean of 250 mg with a standard deviation of 5 mg. from a production line, what percentage of the tablets are expected to contain between 243 and 262 mg of aspirin?What is the 95 % confidence ...
Saturday, September 13, 2008 at 2:06am by jimmy

chemistry
The aspirin content in the analgesic tablets is determined from 120 samples to have a ean of 250 mg with a standard deviation of 5 mg. from a production line, what percentage of the tablets are expected to contain between 243 and 262 mg of aspirin?What is the 95 % confidence ...
Saturday, September 13, 2008 at 6:27pm by Jimmy

statistics
CI95 = mean + or - 1.96(sd divided by √n) ...where + or - 1.96 represents the 95% confidence interval using a z-table, sd = standard deviation, √ = square root, and n = sample size. For the 99% confidence interval, you will have to substitute the value from a z-...
Wednesday, September 30, 2009 at 8:37pm by MathGuru

Statistics
A 95% confidence interval for a population mean, ?, is given as (18.985, 21.015). This confidence interval is based on a simple random sample of 36 observations. Calculate the sample mean, x ?, and the sample standard deviation, s. Assume that all assumptions and conditions ...
Monday, June 18, 2012 at 10:54pm by Mike

statistics
you are constructing a 95% confidence interval using the information: n = 50, xbar = 54.3, s = 2.1 and E = 0.65. What is the value of the middle of the interval?
Wednesday, August 12, 2009 at 10:37pm by jack

Math-Statistics
Find a confidence interval for assuming that each sample is from a normal population. a. P x = 14, = 4, n = 5, 90 percent confidence b. P x = 37, = 5, n = 15, 99 percent confidence c. P x = 121, = 15, n = 25, 95 percent confidence Need to show my work/formula ...
Tuesday, December 6, 2011 at 3:48pm by Richard

BIOLOGY - LAB
What is Confidence Interval? Is it better to have a large Confidence Interval or a small Confidence Interval? Briefly explain.
Tuesday, March 24, 2009 at 12:50pm by biology

stat
A companys CEO wanted to estimate the percentage of defective product per shipment. In a sample containing 500 products, he found 30 defective products. (a) Find a 98% confidence interval for the true proportion of defective product. Show your calculations and/or explain the ...
Saturday, August 20, 2011 at 12:05pm by me,me

Statistics
Explaining confidence. A student reads that a 95% confidence interval for the mean ideal weight given by adult American women is 140 1.4 pounds. Asked to explain the meaning of this interval, the student says, 95% of all adult American women would say that their ideal ...
Sunday, December 1, 2013 at 8:09pm by Mimi

Statistics
A survey of community banks asked about the loan to deposit ratio (LTDR) a banks total loans as a percent of its total deposits. The mean LTDR for the 110 banks in the sample is xbar = 76.7 and the standard deviation is s = 12.3. In the text a 95% confidence interval (using a ...
Monday, February 26, 2007 at 3:35pm by Jason L

Statistics Math
Pye and Associates recently conducted a survey to determine the percent of adult county residents who believe that students in public high schools should wear uniforms to school. The telephone poll of 325 adults found that 35% of the adults believe that public high school ...
Monday, October 28, 2013 at 1:23pm by Michael

statistics
12 squirrels were found to have an average weight of 10.5 ounces with a sample standard deviation is 0.25. Find the 95% confidence interval of the true mean weight
Wednesday, May 8, 2013 at 8:15pm by Anonymous

statistics
how do you get thesampling and confidence intervals for this problem sample scores of 1,2,3,4,5 and 95 percent confidence interval about the sample mean
Friday, October 15, 2010 at 1:39pm by Inez

statistics
Confidence Intervals; In a survey of 1004 individuals, 442 felt that Randolph spent too much time away. Find a 95% confidence interval for the true population proportion
Monday, March 25, 2013 at 10:24pm by ann

Statistics-Confidence Interval
Can someone please help me on how to work this out?? I'm so super confused. Thanks! A professor at Kaplan University claims that the average age of all Kaplan students is 36 years old. Use a 95% confidence interval to test the professor's claim. Is the professor's claim ...
Monday, January 16, 2012 at 7:33pm by Sara

Statistics
Consider the trash bag problem. Suppose that an independent laboratory has tested trash bags and has found that no 30-gallon bags that are currently on the market have a mean breaking strength of 50 pounds or more. On the basis of these results, the producer of the new, ...
Monday, August 31, 2009 at 6:59pm by Amy

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