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April 18, 2014

Homework Help: Math: Statistics

Recent Homework Questions About Statistics

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STATISTICS
is it e or b?
Saturday, August 10, 2013 at 11:39am

Statistics
A study of generator related carbon monoxide deaths showed that a sample of 6 recent years had a variance of 16.8 deaths per year. Find the 99% confidence interval of the true variance
Saturday, August 10, 2013 at 9:55am

Statistics
not sure
Saturday, August 10, 2013 at 9:49am

Statistics
First one is the treatment has no effect
Saturday, August 10, 2013 at 6:23am

statistics
In a simple random sample of 250 father-son pairs taken from a large population of such pairs, the mean height of the fathers is 68.5 inches and the SD is 2.5 inches; the mean height of the sons is 69 inches and the SD is 3 inches; the correlation between the heights of the ...
Saturday, August 10, 2013 at 3:26am

Statistics
In a study of the effect of a medical treatment, a simple random sample of 300 of the 500 participating patients was assigned to the treatment group; the remaining patients formed the control group. When the patients were assessed at the end of the study, favorable outcomes ...
Saturday, August 10, 2013 at 3:20am

Statistics
Stat001 @Din123, well done
Thursday, August 8, 2013 at 11:40pm

statistics
Relative dispersion, sometimes called the coefficient of variation, is the result of dividing the st. dev. by the mean, hence it is dimensionless (it may also be presented as a percentage). So a low value of relative dispersion usually implies that the st. dev. is small in ...
Thursday, August 8, 2013 at 9:35pm

Statistics
A box contains 10 items, of which 3 are defective and 7 are non-defective. Two items are randomly selected, one at a time, with replacement, and x is the number of defective items in the sample. To look up the probability of a defective item being drawn from the box, using a ...
Thursday, August 8, 2013 at 7:25pm

statistics
A study of hours devoted to a graduate course outside of classroom time generates a mean score of 90 with a standard deviation of 20. The mean age of the students was 31 with a standard deviation of 5 years. What is the relative dispersion of the two data sets? A. 2.22%; 1.6% ...
Thursday, August 8, 2013 at 3:05pm

Statistics
Honor Code This can be found at edx org/honor and you are required to follow it. The course staff would like to express their appreciation of all the students who follow the honor code scrupulously. The honor code is not just decoration or boilerplate; it sets out community ...
Wednesday, August 7, 2013 at 10:06pm

Statistics
Why bother doing this class if you're just asking people to give you the answers? It's a free online class with no grades.
Wednesday, August 7, 2013 at 7:14pm

STATISTICS
Thank you MathGuru. This is what I was thinking about.. Sensitivity is the proportion of true positives that are correctly identified by the test. Specificity is the proportion of true negatives that are correctly identified by the test. Positive predictive value = the ...
Wednesday, August 7, 2013 at 6:54pm

STATISTICS
I don't think this can be determined from the information given. You would also have to know the prevalence of the disease in the population. Check this to be sure.
Wednesday, August 7, 2013 at 6:46pm

STATISTICS
A particular diagnostic test for disease X has a sensitivity of 90% and a specificity of 90%. What is the negative predictive value of the test? 90% 10% 1% 18% It cannot be determined from the information given.
Wednesday, August 7, 2013 at 4:13pm

Statistics
@Din123 Thank you
Wednesday, August 7, 2013 at 2:11pm

Statistics
@Helen - i can see that,not sure how the page was deleted,see below incl ur ans PROBLEM 1 ans: E & F PROBLEM 2 ans: C - "The distribution of the cholesterol levels of the residents of the state is close to normal, with an unknown mean and an unknown SD" PROBLEM 3 ans...
Wednesday, August 7, 2013 at 2:10pm

Statistics
A stationary store has decided to accept a large shipment of ball-point pens if an inspection of 20 randomly selected pens yields no more than two defective pens. a) find the probability that this shipment is accepted if 5% of the total shipment is defective. b) find the ...
Wednesday, August 7, 2013 at 10:21am

Statistics
PROBLEM 1 - "E" and "F"
Wednesday, August 7, 2013 at 8:54am

STATISTICS
Which of the following would increase the width of a confidence interval? Changing from a 99% to 95% confidence level. Increasing the variability of the outcome. Increasing the sample size. Removing an outlier from the data
Wednesday, August 7, 2013 at 5:47am

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

STATISTICS
You are performing a cohort study to look at risk factors for breast cancer in postmenopausal women. If the probability of developing breast cancer among smokers is .05 for the study duration, then if you sample 100 smokers, how many do you expect to develop the disease? Give ...
Wednesday, August 7, 2013 at 5:45am

STATISTICS
Thank you Lee!!
Wednesday, August 7, 2013 at 5:43am

STATISTICS
Oh now. I was right. You are wrong!
Wednesday, August 7, 2013 at 5:43am

STATISTICS
Thank you PsyDAG. I hope you had answer before.. I answered the B!
Wednesday, August 7, 2013 at 5:42am

STATISTICS
Thank you guys
Wednesday, August 7, 2013 at 5:40am

Statistics
Thank you stat001 The link you gave us is not directing on a specific question.
Wednesday, August 7, 2013 at 5:38am

STATISTICS
But it is wrong!
Wednesday, August 7, 2013 at 5:32am

STATISTICS
Thank you PsyDAG
Wednesday, August 7, 2013 at 5:30am

STATISTICS
79%
Wednesday, August 7, 2013 at 1:14am

Writing
This time I hope I improve. Writing is a skill that must be practiced. In order to be good at writing I must read a lot, right? I won't survive in college if I am not able to write superfluos essays,right????? *Thank you,Writeacher for your patience. I know you might be ...
Wednesday, August 7, 2013 at 12:53am

STATISTICS (Partial)
SEm = SD/√n
Tuesday, August 6, 2013 at 10:25pm

STATISTICS
If you don't know the right alternative, possibly you could find it by eliminating the false alternatives. Increased variability
Tuesday, August 6, 2013 at 10:23pm

Statistics
-If the null hypothesis were true, there would be about a 3% chance of getting data that were like those that were observed in the sample or even further in the direction of the alternative. -The P-value of about 3% was computed assuming that the null hypothesis was true
Tuesday, August 6, 2013 at 9:00pm

Statistics
have started another question forum with answers to make life easier...... jiskha com/display.cgi?id=1375826423 put a . b/w 1st two words.. site is not allowing me to post weblinks
Tuesday, August 6, 2013 at 6:06pm

Statistics
PROBLEM 4's ans is -2.5
Tuesday, August 6, 2013 at 5:54pm

Statistics
@helen- thank you.. @stat002- answer already posted as "The P-value of the test is closest to ans is 1.5% "
Tuesday, August 6, 2013 at 5:43pm

Statistics
P3 is 11
Tuesday, August 6, 2013 at 5:06pm

STATISTICS
You are performing a cohort study to look at risk factors for breast cancer in postmenopausal women. If the probability of developing breast cancer among smokers is .05 for the study duration, then if you sample 100 smokers, how many do you expect to develop the disease? Give ...
Tuesday, August 6, 2013 at 3:57pm

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 3:57pm

STATISTICS
Standard error: Is always the standard deviation divided by the square root of n. Is a measure of the variability of a sample statistic. Increases with bigger sample sizes. All of the above.
Tuesday, August 6, 2013 at 3:54pm

STATISTICS
Which of the following would increase the width of a confidence interval? Changing from a 99% to 95% confidence level. Increasing the variability of the outcome. Increasing the sample size. Removing an outlier from the data
Tuesday, August 6, 2013 at 3:52pm

STATISTICS
A study was conducted to examine the peer review process. The investigators hypothesized that reviewers suggested by authors would give more favorable reviews than reviewers picked by journal editors. They obtained data on 40 manuscripts that had been reviewed by 1 author-...
Tuesday, August 6, 2013 at 3:50pm

STATISTICS
In a survey of 1000 registered U.S. voters, 55% respond that they support health care reform. What is the 95% confidence interval for the true percentage of U.S. registered voters who support health care reform? 50%-60% 55%-60% 51%-59% 52%-58% 49%-47%
Tuesday, August 6, 2013 at 3:48pm

STATISTICS
The following table comes from a hypothetical case-control study that compared adults with moderate-to-severe acne (cases) to adults without acne (controls). The researchers examined the relationship between smoking and acne. The prevalence of moderate-to-severe acne in the ...
Tuesday, August 6, 2013 at 3:48pm

STATISTICS
Assume that the probability of developing lung cancer in smokers is 15%; the probability of developing lung cancer in non-smokers is 1%; and the prevalence of smokers in the U.S. is 20%. If a person is diagnosed with lung cancer, what is the probability that he/she is a smoker...
Tuesday, August 6, 2013 at 3:46pm

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

STATISTICS
Researchers conducted a case-control study to identify risk factors for kidney cancer. They asked 50 cases and 50 controls about 100 different exposures and personal characteristics, and calculated the odds ratio for kidney cancer for each risk factor. They found statistically...
Tuesday, August 6, 2013 at 3:43pm

STATISTICS
In a psychology experiment in which 100 volunteers were asked to read a paragraph about an engineer, 65 assumed that the engineer was male despite the fact that the paragraph did not specify gender (and avoided gendered pronouns such as “he” or “she”). ...
Tuesday, August 6, 2013 at 3:42pm

STATISTICS
Researchers reported that in a sample of U.S. women aged 50 to 54 who underwent mammography, 14.4% were recalled for further evaluation; however, in a similar sample of women undergoing mammography in the United Kingdom, only 7.6% were recalled for further evaluation. What are...
Tuesday, August 6, 2013 at 3:42pm

STATISTICS
A particular diagnostic test for disease X has a sensitivity of 90% and a specificity of 90%. What is the negative predictive value of the test? 90% 10% 1% 18% It cannot be determined from the information given
Tuesday, August 6, 2013 at 3:41pm

Statistics
can anyone let me know the answer to PROBLEM 1 - A statistical test is performed, and its P-value turns out to be about 3%. Which of the following must be true? Pick all that are correct. PROBLEM 3 - The t distribution that should be used has ______ degrees of freedom. PROBLEM...
Tuesday, August 6, 2013 at 3:41pm

Statistics
Does anybody know the P4 and P5 answers? P4: -2.6 -2.1 and -2.3 are wrong P5: 1%, 2.5%, and 0.5% are wrong
Tuesday, August 6, 2013 at 3:39pm

Statistics
PROBLEM 8 ans is 1.8
Tuesday, August 6, 2013 at 3:23pm

Statistics
PROBLEM 9 ans is 3
Tuesday, August 6, 2013 at 3:20pm

Statistics
PROBLEM 7 ans is 14.5
Tuesday, August 6, 2013 at 3:20pm

Statistics
question number 10 ans is "one-sample z = (2.95 - 2.9)/0.055 = 0.909; P large; conclude chance variation"
Tuesday, August 6, 2013 at 3:14pm

Statistics
The P-value of the test is closest to ans is 1.5%
Tuesday, August 6, 2013 at 3:12pm

Statistics
Do not try the answers they tell you. We have many stupids here with psycho problems. They tell you randomly the answers to try for them!
Tuesday, August 6, 2013 at 1:17pm

Statistics
Need answer to P 10
Tuesday, August 6, 2013 at 10:34am

Statistics
Blossom's Flowers purchases roses for sale for Valentine's Day. The roses are purchased for $10 a dozen and are sold for $20 a dozen. Any roses not sold on Valentine's Day can be sold for $5 per dozen. The owner will purchase 1 of 3 amounts of roses for Valentine&#...
Tuesday, August 6, 2013 at 10:27am

Statistics
The questions 2, 3 and 4 are wrong
Tuesday, August 6, 2013 at 8:16am

statistics
On average, you receive four pieces of junk mail a day. For a randomsample of 10 weekends find the probability that at least 8 weekends youreceive exactly three pieces of junk mail?
Tuesday, August 6, 2013 at 6:39am

Statistics
What are the wrong answer?
Monday, August 5, 2013 at 1:38pm

statistics
http://www.google.com/search?client=safa​ri&rls=en&q=type+i+and+type+ii+errors&ie​=UTF-8&oe=UTF-8
Monday, August 5, 2013 at 1:05pm

Statistics
this test is easy listen the videos and do the exercises of those videos and it's easy. If you have any doubt just ask.
Monday, August 5, 2013 at 12:45pm

Statistics
Some answers are wrong.
Monday, August 5, 2013 at 9:02am

statistics
Identify the type I error and the type II error that is a hypothesis. The percentage of households with more than 1 pet is equal to 65%
Sunday, August 4, 2013 at 7:37pm

Statistics
QUESTION 1. The distribution of the cholesterol levels of the residents of the state is close to normal, with an unknown mean and an unknown SD. QUESTION 4 2% QUESTION 5 reject the null hypothesis QUESTION 2 2 QUESTION 3 -2.3
Sunday, August 4, 2013 at 2:17pm

Statistics
The distribution of cholesterol levels of the residents of a state closely follows the normal curve. Investigators want to test whether the mean cholesterol level of the residents is 200 mg/dL or lower. A simple random sample of 12 residents has a mean cholesterol level of 185...
Sunday, August 4, 2013 at 11:23am

Statistics
A statistical test is performed, and its P-value turns out to be about 3%. Which of the following must be true? Pick all that are correct. The null hypothesis is true. There is about a 3% chance that the null hypothesis is true. The alternative hypothesis is true. There is ...
Sunday, August 4, 2013 at 11:19am

Statistics
Mean=300*0.5=150 SD=SQRT(300*0.5*(1-0.5))=8.66 Z=+/- (170.5-150)/8.66 = +/- 2.37 Table of Z P= 2*0.0089 = 1.78% +/- because we have two-tailed and multiple the value of P by 2 for the same reason
Sunday, August 4, 2013 at 5:33am

Statistics
2.33 84.13
Saturday, August 3, 2013 at 5:14pm

Statistics
Hola ¿Cuál es el P - value en este problema que escribiste?
Saturday, August 3, 2013 at 11:58am

Statistics
Hi CC, Thanks for the ans. I also want to know how to calculate this value? How did u get 1.78? Once again thanks for the ans.
Saturday, August 3, 2013 at 6:55am

Statistics
Hey :) could you please tell me how did you get the answer 1.78 ??? I want to know how to calculate it. Thanks a lot for your help!
Saturday, August 3, 2013 at 5:59am

statistics
There are two boxes, each with several million tickets marked “1” or “0”. The two boxes have the same number of tickets, but in one of the boxes, 49% of the tickets are marked “1” and in the other box 50.5% of the tickets are marked “1”...
Friday, August 2, 2013 at 6:40pm

Statistics
thanks :) had achieved good luck to the course excuse the English'm from Portugal
Friday, August 2, 2013 at 6:12pm

statistics
Archie must travel to a foreign country where a deadly strain of flu has ravaged the population. Already, 34% of the population has succumbed to the flu and died. There is a vaccine, but because the flu is extremely contagious, it spreads quite rapidly, and to date only 1 out ...
Friday, August 2, 2013 at 6:06pm

english
If you go to the Internet and do a research for statistics to back up your argument for a speech you are writing for your Communications class, it is considered: A. primary research. B. investigative research. C. systematic research. D. secondary research.
Friday, August 2, 2013 at 4:57pm

Math Statistics
Suppose a large-scale randomized experiment were conducted to compare two weight loss plans. At the end of the experiment, the weight loss for each subject (in pounds) was recorded. The p-value turned out to be .004, and a 99% confidence interval for the difference in means ...
Friday, August 2, 2013 at 1:51pm

Statistics
To CC, 2 is B, 6 is B
Friday, August 2, 2013 at 12:34pm

Statistics
you know the correct answer to the problem 2 and 6 of the test? The P-value (problem 8) is 1.78 (it is correct)
Friday, August 2, 2013 at 9:58am

Statistics
Thanks youre right bud!
Friday, August 2, 2013 at 5:56am

Statistics
A statistics student hands each of 300 classmates 2 cookies side by side on a plate. Of the 300 students, 171 choose the cookie that’s on their right hand side, and the remaining 129 choose the cookie that’s on their left. The student says, “That’s just ...
Friday, August 2, 2013 at 4:52am

statistics
Yes there is enough evidence to support---- T = (16-15.6)/(.3/sqrt(8)) df = n-1 df = 8-1 = 7 critical t value = 1.895
Friday, August 2, 2013 at 1:32am

statistics
Yes there is enough evidence to support---- T = (16-15.6)/(.3/sqrt(8)) df = n-1 df = 8-1 = 7 critical t value = 1.895
Friday, August 2, 2013 at 1:31am

statistics
A machine is designed to fill jars with 16 ounces of coffee. A consumer suspects that the machine is not filling the jars completely. A sample of 8 jars has a mean of 15.6 ounces and a standard deviation of 0.3 ounce. Is there enough evidence to support the consumer's ...
Friday, August 2, 2013 at 12:44am

statistics
Suppose a large-scale randomized experiment were conducted to compare two weight loss plans. At the end of the experiment, the weight loss for each subject (in pounds) was recorded. The p-value turned out to be .004, and a 99% confidence interval for the difference in means ...
Thursday, August 1, 2013 at 10:41pm

Statistics
There are two boxes, each with several million tickets marked “1” or “0”. The two boxes have the same number of tickets, but in one of the boxes, 49% of the tickets are marked “1” and in the other box 50.5% of the tickets are marked “1...
Thursday, August 1, 2013 at 1:21pm

Statistics
I think it will be 1,78% then confirm if that was the correct answer
Thursday, August 1, 2013 at 11:06am

Statistics
why D?
Thursday, August 1, 2013 at 10:14am

Statistics
no its D
Thursday, August 1, 2013 at 9:37am

statistics
A sample of 100 iron bars is said to be drawn from a large number of bars. Whose lengths are normally distributed with mean 4 feet and S.D 0.6ft. If the sample mean is 4.2 ft, can the sample be regarded as a truly random sample?
Thursday, August 1, 2013 at 9:37am

Statistics
I would say the alternate hypothesis is rejected
Thursday, August 1, 2013 at 6:46am

Statistics
4257/5352
Thursday, August 1, 2013 at 4:23am

statistics
448/450
Thursday, August 1, 2013 at 4:22am

Statistics
A statistics student hands each of 300 classmates 2 cookies side by side on a plate. Of the 300 students, 171 choose the cookie that’s on their right hand side, and the remaining 129 choose the cookie that’s on their left. The student says, “That’s just ...
Thursday, August 1, 2013 at 2:25am

statistics
After one month of operation the health information services at community health center determined that there were two reords misfiled out of the 450 active records. What is the filing accuracy rate for this area?
Thursday, August 1, 2013 at 12:28am

Statistics
after one month of operation the health information services at community health center determined that there were two records misfiled out of the 450 active records. what is the filing accuracy rate for this area?
Thursday, August 1, 2013 at 12:22am

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