Search: statistics/mean and standard deviation

Number of results: 36,332

Probability and Statistics
A research psychologist believes that professional athletes tend to be more confident than the typical person. From previous testing, he knows that the scores for people in the general population are approximately normally distributed with a mean of 72 and standard deviation ...
Sunday, April 29, 2012 at 7:52pm by Kim

statistics
90% = mean ± 2.035 SD 2.035 was found by finding table in the back of a statistics text labeled something like "areas under normal distribution" to find the proportion (.45) between score and mean to get the Z score (value in terms of standard deviation).
Sunday, November 27, 2011 at 9:05pm by PsyDAG

statistics
I assume that the mean = 120, the standard deviation = 18 with a sample of 36. However, I don't know what "o" signifies. A population has parameters, but a sample — which you indicate this is ("sampling") — has statistics.
Wednesday, January 18, 2012 at 5:31pm by PsyDAG

statistics
a. A statistics practitioner randomly sampled 100 observations from a population with a standard deviation of 5 and found that x is 10. Estimate the population mean with 90% confidence.
Monday, August 15, 2011 at 11:00pm by Sally

stats
does this formula look familar? z= (x-mean)/(standard deviation) Find the z-score that matches 4%. Then, plug in that for z. Finally, solve for standard deviation.
Monday, September 24, 2007 at 9:38pm by Anonymous

Statistics
In recording the self-reported lengths of a particular body part in a sample of male undergraduates, the largest was claimed to be 20 cm—a full 3 standard deviations from the mean length for the sample. The shortest alleged length was only 10 cm, which was equivalent to ...
Saturday, November 3, 2012 at 11:31pm by susan

statistics
it is stated that the standard deviation sample of the is 7.6 (n = 26). Test the claim to a significance level of 0.10 that the population standard deviation was greater than 7.0. Round all answers to 3 decimal places.
Saturday, July 28, 2012 at 1:40pm by geety

university of phoenix
if someone scored two standard deviations above the mean on a standard test where the mean =100 and the standard deviation = 15, what is the person's numerical score?
Friday, July 13, 2012 at 8:19pm by benjamin

statistics
Z = (raw score - mean)/ standard deviation Percentages from Z scores can be found in a table in the back of your statistics text labeled something like "areas under the normal distribution." I hope this helps. Thanks for asking.
Wednesday, September 10, 2008 at 7:41pm by PsyDAG

math
Statistics: Analyze student exam scores Students were given an exam with 300 multiple choice questions. The distribution of the scores were normal and the mean was 195 with a standard deviation of 30. you may find it helpful to draw out this distribution before answering the ...
Wednesday, March 21, 2012 at 6:01pm by ro

statistic
1. A distribution has a standard deviation of 12. Find the z-score for each of the following locations in the distribution. a. Above the mean by 3 points. b. Above the mean by 12 points. c. Below the mean by 24 points. d. Below the mean by 18 points. For the ...
Saturday, January 26, 2013 at 6:45pm by Nickie

Math
Are you sure that second formula isn't Ó(x-ì)²F? Unless it is, I can't see a way of calculating a standard deviation from the statistics supplied. On the assumption that the second statistic is Ó(x-ì)²F, the variance ought to be (1...
Friday, October 3, 2008 at 5:20am by David Q

statistics
A student scores 600 on a SAT test. If the population mean of the test scores is 510 and the population standard deviation is 106 point, what is the student’s deviation from the mean?
Thursday, December 8, 2011 at 3:13am by violet

statistics
I.use the chebyshev's theorem to find out what percentage of the values will fall between 201 and 257 for a data set with a mean of 229 and standard deviation of 14. II. use the emperical rule to find out two values 68% of the data will fall between for a data set with a ...
Monday, October 11, 2010 at 11:16pm by mary

statistics
The standard error (SE) of the mean is the standard deviation (SD) divided by the square root of the number in the sample. In this case, your Z score would be ($1075-$1100)/SE. Find the Z score and look it up in the back of your statistics text in a table labeled something ...
Saturday, September 13, 2008 at 5:12pm by PsyDAG

Statistics...help
An article claimed that the typical supermarket trip takes a mean of 22 minutes. suppose that in an effort to test this claim, you select a sample of 50 shoppers at a local supermarket. the mean shopping time for the sample of 50 shoppers is 25.36 min. with a standard ...
Thursday, April 3, 2008 at 2:26pm by tanya

statistics
Standard deviation = square root of variance. Z = (score-mean)/SD
Friday, April 19, 2013 at 2:36pm by PsyDAG

statistics
The new mean will be 25+ 50 = ? The standard deviation will remain the same.
Saturday, April 28, 2012 at 10:17pm by PsyDAG

Statistics
Central tendency is to ________ as mean is to standard deviation. This is in a crossword puzzle. _ _ R _ A _ _ _ _
Thursday, January 29, 2009 at 8:02pm by Anonymous

Statistics- Math
One student scored 54 on a math test for which the mean score was 50.5 and the standard deviation was 3.2. Another student scored 80 on a chemistry test for which the mean score was 75.2 and the standard deviation was 5.2. Which student (math or chemistry) had a "better&...
Friday, February 17, 2012 at 12:00pm by Kerrin

Math
Can someone explain what to do for the following question. What percentage of a normal distribution is greater than the mean? Give your answer correct to the nearest percent. What formula is used? Because I have to find also 1 standard deviation of the mean and what percentage...
Wednesday, May 22, 2013 at 11:01pm by Sue

Statisitcs
I have given you the information from 2-4 in hopes to help with the answer for #6.. Thank you! 2. Calculate the mean and standard deviation of the probability distribution created by rolling a die. Either show work or explain how your answer was calculated. x 1 2 3 4 5 6 sum p...
Thursday, October 6, 2011 at 4:42pm by Hope

Statistics
Need the mean and standard deviation values. 95% conf. interval = mean ± 1.96 SE SE = SD/√(n-1)
Friday, June 25, 2010 at 9:37am by PsyDAG

adult education
The lifetimes of lightbulbs of a particular type are normally distributed with a mean of 290 hours and a standard deviation of 6 hours. What percentage of the bulbs have lifetimes that lie within 1 standard deviation to either side of the mean?
Saturday, May 23, 2009 at 4:57pm by sally

Statistics
Z = (score - mean)/SD Z = (58.5-62)/ 3.5 = -1 Z = (72.5-62)/3.5 = 3 It goes from one standard deviation below the mean to 3 above. Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions related ...
Sunday, June 20, 2010 at 11:09am by PsyDAG

statistics
Mean = 100 One standard deviation above the mean = 15 Two standard deviations above the mean = 15 + 15 = 30 Therefore: 100 + 30 = 130
Monday, February 20, 2012 at 9:13pm by MathGuru

statistics
Your values are the following: p = .45, q = 1 - p = .55, x = 45, and n = 110 Use the normal approximation to the binomial distribution. Find mean and standard deviation. mean = np = (100)(.45) = ? sd = √npq = √(100)(.45)(.55) = ? Once you determine the mean...
Sunday, September 26, 2010 at 6:53pm by MathGuru

statistics
worried about customer complaints and potential lawsuits, the manufacterers decided that no more than o.5% of bags of Crunchy corn chips should be underweight. there are 2 possible adjustments that can be made; change the mean setting on the filling machines while leaving the ...
Wednesday, October 10, 2007 at 8:31am by sophs

statistics
I don't know what you mean by the "five number summary." Could they be mean, mode, median, standard deviation and range? Find the mean first = sum of scores/number of scores Subtract each of the scores from the mean and square each difference. Find the sum of ...
Wednesday, March 7, 2012 at 8:28am by PsyDAG

statistics
Sample with size n = 100 has mean = 30. Assuming the population standard deviation is 8, construct 95% confidence interval for population mean.
Wednesday, February 22, 2012 at 6:29pm by Tina

statistics
Formula for a t-test: t = (sample mean - population mean)/(standard deviation divided by the square root of the sample size) I'll let you take it from here.
Sunday, April 24, 2011 at 6:34pm by MathGuru

Statistics
What test statistic are you seeking? Mean? Mode? Median? Standard deviation? Mean = μ = (Σx)/n = 20/15 = 1.333 Is that what you were seeking?
Saturday, March 27, 2010 at 2:57pm by PsyDAG

statistics...Please help
A sample of 12 measurements has a mean of 24 and a standard deviation of 4.5. Suppose that the sample is enlarged to 14 measurements, by including two additional measurements having a common value of 24 each. Find the standard deviation of the sample of 14 measurements.
Saturday, January 24, 2009 at 11:20pm by JT

MATH
A mean score on a standardized test is 50 with a standard deviation of 10. Answer the following a. What scores fall between –1 and +1 standard deviation? b. What percent of all scores fall between –1 and +1 standard deviation? c. What score falls at +2 standard ...
Tuesday, April 3, 2012 at 10:20pm by Bridget

statistics
5) The lifetime of a medical device s a normally distributed rv with standard deviation of 2 years. An experiment is conducted to test 15 medical devices and find their lifetimes to be: a. If the population mean is known to be 15 years, what is the probability that the mean ...
Saturday, December 8, 2012 at 4:10pm by nur

Statistics
Data from the latest census was analyzed. It was determined that one-parent households spend less on food away from home that do two-parent households. The mean amount spent by 30 one-parent households is $1876 and the standard deviation is $113. The mean amount spent by 30 ...
Wednesday, April 4, 2012 at 4:50pm by Mike

statistics
Calculate the mean and standard deviation for each machine. Z = (mean1 - mean2)/standard error (SE) of difference between means SEdiff = √(SEmean1^2 + SEmean2^2) SEm = SD/√(n-1) Find table in the back of your statistics text labeled something like "...
Friday, September 24, 2010 at 10:46am by PsyDAG

statistics
The mean length of a work week for the population of workers was reported to be 39.2 hours. Suppose that we would like to take a current sample of workers to see whether the mean length of a work week has changed from the previously reported 39.2 hours. a. State the hypotheses...
Sunday, April 29, 2012 at 12:22pm by frances

statistics (incomplete)
What is the mean and standard deviation for the sample? Z = (score-mean)/SEm SEm = SD/√n Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion (±.425) related to the Z score.
Wednesday, October 3, 2012 at 9:42pm by PsyDAG

statistics
What is the mean and standard deviation of the distribution of normal temperatures? Z = (100.6 - mean)/SD Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to this Z score. Come to ...
Monday, May 10, 2010 at 11:54pm by PsyDAG

statistics
A sample of 12 measurements has a mean of 20 and a standard deviation of 2. Suppose that the sample is enlarged to 14 measurements, by including two additional measurements having a common value of 20 each. Find the standard deviation of the sample of 14 measurements.
Tuesday, October 11, 2011 at 2:28pm by Bob

Statistics
A sample of 12 measurements has a mean of 24 and a standard deviation of 4.5. Suppose that the sample is enlarged to 14 measurements, by including two additional measurements having a common value of 24 each. Find the standard deviation of the sample of 14 measurements?
Saturday, January 24, 2009 at 11:07pm by Nao

Statistics
A population has a mean of 200 and standard deviation of 50 and simple random sample size of 100 and x is used to estimate u. What is the probility that the sample mean will be within plus or minue 5 of the population mean?
Monday, May 10, 2010 at 10:37am by Vroni

statistics
A researcher wishes to estimate the mean height of women aged between 60 and 65 in the US. She desires a margin of error of 0.2 inches. Past studies suggest that a population standard deviation deviation of 3.2 inches is reasonable. Estimate the minimum sample size needed to ...
Monday, January 23, 2012 at 10:02pm by dan

statistics
Help me! Population of heights of college students is approximately normally distributed with a mean of 64.37 inches and standard deviation of 6.26 inches A random sample of 74 heights is obtained. Find the mean and standard error of the x bar distribution 2. Find P(xbar &...
Sunday, November 6, 2011 at 7:28pm by anon

statistics
Can someone provide me with some assistance in answering this question.. A company manufacturers batteries in BATCHES of 18 and there is a 3% rate of defect. Find the standard deviation for the number of defects per batch. The probability of a defect is p = 0.03 The mean ...
Sunday, August 5, 2007 at 9:45am by john

STATISTICS
Use a normal approximation to the binomial distribution. Your values are the following: p = .52, q = 1 - p = .48, x = 1, and n = 3 Find mean and standard deviation. mean = np = (3)(.52) = ? sd = √npq = √(3)(.52)(.48) = ? I'll let you finish the ...
Wednesday, September 29, 2010 at 9:50pm by MathGuru

STAT
A population has a standard deviation ó of 23 units. (Give your answers correct to two decimal places.) (a) Find the standard error for the mean if n = 11. (b) Find the standard error for the mean if n = 41. (c) Find the standard error for the mean if n = 85.
Wednesday, April 3, 2013 at 11:46pm by Jane

statistics
Mean = 22.53 Variance = 13.8969 Standard deviation = 3.72785
Monday, October 11, 2010 at 11:20pm by Shereen

statistics
Approximately 68% of scores occur between mean ± one standard deviation. Does that help?
Tuesday, January 31, 2012 at 10:42pm by PsyDAG

statistics
Assume that a population is normally distributed with a mean of 100 and a standard deviation of 15.
Monday, September 26, 2011 at 10:30am by michelle

statistics
if a data set has mean 70, and standard deviation 5, is 80 asuspect outliner/
Thursday, September 15, 2011 at 9:25pm by shana

statistics
Which part of this assignment don't you understand? mean? median? range? standard deviation?
Saturday, August 13, 2011 at 6:28pm by Ms. Sue

statistics
I don't know what "q0" means, but standard deviation (error) of the mean (SEm) = SD/sqrt (n-1)
Wednesday, July 6, 2011 at 11:11pm by PsyDAG

Statistics
The mean of a data set is 23 and 12.6. The z-score is -1.30. What is the standard deviation?
Sunday, June 26, 2011 at 6:24pm by Shelle

statistics
in a distribution of scores with a mean of 1500 and a standard deviation of 250, what is the 95th percentile?
Saturday, February 26, 2011 at 9:48am by Ruben

statistics
Suppose X is N(4,2) and Y is N(10,1). what kind of distribution is 2X+Y? What is its mean and standard deviation if X and Y are independent?
Tuesday, January 4, 2011 at 6:56am by Corey

college statistics
If a set of data has mean=12 and standard deviation=3, then the coefficient of variation is [x]%
Wednesday, October 6, 2010 at 8:39pm by tera

STATISTICS
What are the values on this particular distribution? Mean? Standard deviation? More data needed.
Thursday, June 3, 2010 at 3:23pm by PsyDAG

statistics
Z = (score-mean)/Standard deviation Fill in the respective values and solve for the SD.
Wednesday, March 10, 2010 at 9:18pm by PsyDAG

statistics
If sample number is 1,000 and mean is 7.2 on a scale from 1-10 how do I determine standard deviation.
Saturday, February 13, 2010 at 6:09pm by mark

math30
The Mean and the Standard Deviation Last year, golfers at Smith Ranch golf course had a mean score of 41 and a standard deviation of 2 on the first nine holes of the course, and a mean of 38 and a standard deviation of 1.8 on the last nine holes. One afternoon, Nathan scored ...
Wednesday, February 13, 2013 at 3:17am by alejandro

Statistics
New data is added to change the mean time to 6 mninutes and 10 seconds with standared deviation 2 minutes and 5 seconds. The mean depth is now 115.5 feet with standard deviation 31.6 feet. If the association is still negative and r^2=.68, find the slope of the regression line ...
Wednesday, March 7, 2012 at 9:09am by Shayla

statistics
Find mean and standard deviation. Use z-scores to find z, then a z-table to find your probability based on the z-score. This is a normal approximation to the binomial distribution. I'll get you started: mean or expected value = np = (15)(.40) = ? standard deviation = &...
Saturday, March 26, 2011 at 11:50pm by MathGuru

Statistics
I have a question that involves explaining what is wrong in each of the following situations: (a) A random sample of size 20 is taken from a population that is assumed to have a standard deviation of 12. The standard deviation of the sample mean is 12/20. (b) A researcher ...
Sunday, March 29, 2009 at 11:13pm by Lynn

math
Well, it certainly isn't B; that is much too large. And it isn't C, because 39.5 is the mean. That leaves A) or D). Are you familiar with the definition of standard deviation? You should go ahead and calculate it. It isn't that hard. The individual deviations from ...
Sunday, December 13, 2009 at 2:17am by drwls

statistics
A final exam in sociology has a mean of 72 and a standard deviation of 9.2. If 35 students are randomly selected, find the probability that the mean of their test scores will be greater than 76. Round to tenth of a percent
Wednesday, June 13, 2012 at 11:25am by Anonymous

Statistics
Which of the following is NOT sensitive to extreme values? A) the range B) the standard deviation C) the interquartile range D) the coefficient of variation I pick B the standard deviation
Friday, May 27, 2011 at 10:56am by Alex

statistics
I assume that x refers to the mean, but I am not sure. What is the standard deviation (SD)? 98% are within μ ± 2.33 SE (Standard Error of the Mean) ( Got the above by looking at table of proportions under the normal distribution in the back of a statistics text...
Sunday, December 6, 2009 at 10:44pm by PsyDAG

statistics
a.a statistics practitioner randomly sampled 100 observations from a population with a standard deviation of 5 and found that x is 10. Estimate the population mean with 90% confidence. Repeat (a) with a sample sixe of 25
Sunday, October 16, 2011 at 9:12pm by lisa

statistics
, which is the probability that the mean fat content in farm-raised trout is grams per pound or less. The sample is drawn from a population with mean and standard deviation . We do not know the shape of the population distribution, though, so it would seem that we have too ...
Sunday, October 23, 2011 at 8:45am by Ms. Lynn

statistics
Data from the latest census was analyzed. It was determined that one-parent households spend less on food away from home that do two-parent households. The mean amount spent by 30 one-parent households is $1876 and the standard deviation is $113. The mean amount spent by 30 ...
Wednesday, April 18, 2012 at 7:46pm by Mike

statistics
If the average number of textbooks is 16, the standard deviation is 5, and the average age of a professors is 43, with a standard deviation of 8, which data set is more variable?
Sunday, March 10, 2013 at 3:50pm by ann

Statistics- I think I have the answer
Your pick is incorrect. It's either c) or d). Remember that standard deviation is the square root of the variance, and variance is standard deviation squared.
Sunday, March 29, 2009 at 4:49pm by MathGuru

Statistics
First find the allowed standard deviation for the sample average. Then find the number of members of the group to needed reduce the standard deviation to that value.
Monday, December 8, 2008 at 3:29am by drwls

Statistics
If the standard deviation of a sample is 4.3 for 28 data values, what would the standard deviation be fore the population from which the sample was drawn?
Wednesday, January 30, 2013 at 7:19pm by Leisa

Math
Would you rather take an exam that typically has an mean of 80 with a standard deviation of 3 or an exam with a mean of 80 with a standard deviation of 15? why?
Friday, December 3, 2010 at 8:19am by Rena

Math
Would you rather take an exam that typically has an mean of 80 with a standard deviation of 3 or an exam with a mean of 80 with a standard deviation of 15? why?
Thursday, December 2, 2010 at 9:55pm by Rena

Statistics: Range, Average Deviation, Standard Dev
Thanks for the instructions. I will work on it now that I have thorough instructions on how to come up with the range, average deviation, and standard deviation.
Tuesday, October 18, 2011 at 1:44am by Joy Chapman

math
You are given the following: there are 27 pieces of data mean is 60 standard deviation is 25 You realize that one of the pieces of data is inputted wrong..... it was a 25, but it is suppose to be 52.... find the actual mean and standard deviation for the actual set of numbers ...
Monday, October 9, 2006 at 9:55pm by jj

Business Statistics
1. Suppose that the mean of the annual return for common stocks from 1950 to 2012 was 9.4%, and the standard deviation of the annual return was 17.5%. Suppose also that during the same 62-year time span, the mean of the annual return for long-term government bonds ...
Wednesday, March 6, 2013 at 9:34am by Michelle

Statistics
a) Find the mean first = sum of scores/number of scores Subtract each of the scores from the mean and square each difference. Find the sum of these squares. Divide that by the number of scores to get variance. Standard deviation = square root of variance Standard deviation of ...
Sunday, May 5, 2013 at 2:25pm by PsyDAG

statistics
z/sigma = score - mean 2 sigma = 88 - mean -sigma = 79 - mean subtract second equation from first. 3 sigma = 9 sigma = 3 is the standard deviation Use either equation to get the mean
Tuesday, February 5, 2008 at 1:25am by drwls

math (statistics
John's z-score on a college entrace exam is 1.3. If the raw scores have a mean of 480 and a standard deviation of 70 points, what is his raw score? Use a z-score formula to find John's raw score. The formula: z = (x - mean)/sd -->sd = standard deviation Using ...
Thursday, January 18, 2007 at 9:25pm by Joe

stats please help ASAP!!!
A. The GPAs of all 5540 students enrolled at a University have an approximately normal distribution with a mean of 3.02 and a standard deviation of 0.29. Let x be the mean GPA of a random sample of 48 students selected from this University. Find the mean and standard deviation...
Friday, May 17, 2013 at 2:06am by DON

math
i have two two judges convicting a robberer judge a mean is 33.0 and standard deviation is 2.0. judge b has a mean of 30.0 and a standard deviation of 8.1. which judge would the robber want to sentence?
Friday, July 29, 2011 at 12:05pm by patricia

Probability and statistics
Question 1 of 1: Finding Standard Deviation A simple random sample of FICO credit rating scores is listed below: 714 751 664 789 818 779 698 836 753 834 693 802 Find range, variance, and standard deviation. As of this writing, the mean FICO score was reported to be 678. Based ...
Friday, March 2, 2012 at 3:23am by Anonymous

statistics
a. A random sample of 25 was drawn from a normal distribution with a standard deviation of 5. The sample mean is 80. Determine the 95% confidence interval estimate of the population mean.
Monday, August 15, 2011 at 10:59pm by Sally

Statistics
For a sample group of 22, the mean is 86 with a standard deviation of 5. What is the 90% confidence interval of the true mean of the sample? Can you please explain the steps you used to get the answer. Thanks.
Sunday, October 24, 2010 at 10:01pm by Anon

Essentials of statistics
A populations of scores forms a normal distribution with a mean of 40 and a standard deviation of 12 what is the probability of selecting a sample of n=9 scores with a mean less than m=34
Saturday, July 31, 2010 at 9:29pm by Anonymous

Statistics
he Oil Price Information Center reports the mean price per gallon of regular gasoline is $ 3.79 with a population standard deviation of $ 0.18. Assume a random sample of 40 gasoline stations is selected and their mean cost for regular gasoline is computed. 1. What is the ...
Sunday, September 26, 2010 at 5:25pm by John

statistics
Find mean and standard deviation. Use z-scores to find z, then a z-table to find your probability based on the z-score. This is a normal approximation to the binomial distribution. I'll get you started: mean = np = (500)(.56) = ? standard deviation = √npq = &...
Thursday, March 31, 2011 at 12:40am by MathGuru

STATISTICS
First, relax 1) With your sample of 30, calculate the mean (average) travel time and the standard deviation. (I presume you know how to do these calculations). 2) Calculate the number of standard deviations that 45 minutes is away from the mean. That is X=(mean-45)/SD (mean ...
Sunday, December 16, 2007 at 4:05pm by economyst

statistics
More data needed. What is the mean and standard deviation of the baggage weights? Is 195 a typo?
Wednesday, November 9, 2011 at 5:48pm by PsyDAG

statistics
if a test has a mean of 75, with a standard deviation of 11, what % of students scored an A (90 or higher)?
Tuesday, May 31, 2011 at 12:35am by cathy

statistics
For a population with a mean of 30 and standard deviation of 6, describe the sampling distribution of the means for samples of N=9.
Tuesday, November 3, 2009 at 4:32pm by Ashley

Math - Standard Deviation
A General Electric soft white 3-way bulb has an average life of 1200 hours with a standard deviation of 50 hours. Find the probability that the life of one of these bulbs will be between 1150 and 1300 hours. You need to change the times to Z-scores â€” scores ...
Friday, July 22, 2005 at 1:24am by GetYourLeash

statistics
A final exam in Math 157 is normally distributed and has a mean of 75 with a standard deviation of 12. If 36 students are randomly selected, find the probability that the mean of their test scores is greater than 70.
Wednesday, June 22, 2011 at 8:11pm by Jessica

Pages: <<Prev | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | Next>>

For Further Reading