Which of the following sets of data would produce the largest value for Cohen’s d if the difference between the samples is 5 points? ​ Select one: a. ​ n = 15 for both samples and a pooled variance of 15 b. ​ n = 90 for both samples and a pooled variance of 15 c. ​ Cohen’s d is the same for all three of the samples. d. ​ n = 5 for both samples and a pooled variance of 15

The next seven questions refer to the following scenario: A random sample of 16 Porsche drivers yielded an average age of 50 years with a variance of 9 years and a random sample of also 16 Ferrari drivers yielded an average of 47 years with a variance of 25 years. Porsche Driver Ferrari Driver n 16 16 mean 50 47 Variance 25 Conduct the following hypothesis test at a=0.05. HO: Mean Age Porsche Drivers Mean Age Ferrari Drivers Assume unequal variance.

Please complete the following:   Explain in a sentence what a certain Cohen’s d means.   Explain in a sentence what a certain variance (r2) means.   What are the magnitudes of effect sizes for Cohen’s d?   What are the magnitudes of effect sizes for variance (r2)?

Two students sit for a university final exam whose scores are known to be normally distributed. The raw scores of the students are 63 and 93, and the z scores (standardized scores) of these scoresare -1 and 1.5 respectively. What is the variance of the distribution of raw exam scores?

One sample has SS = 60 and a second sample has %3D SS = 48. a. If n = 7 for both samples, find each of the sample %3D variances, and calculate the pooled variance. Because the samples are the same size, you should find that the pooled variance is exactly halfway between the two sample variances.

Suppose that 67% of college students in Australia use more than 1.65 gigabytes of data ontheir mobile phone per month.  If the monthly mobile data usage by college students isnormally distributed with variance of 2.25, what will be the average mobile data usage?a. 0.66 b. 0.99 c. 2.31 d. 2.64

A group of 8 students reported the number of hours they studied for their MTH107 test. The results are as follows.  0          0          1          3          4          7          8          9 Choose which of the following correctly represents the variance of the data set correct to four decimal places.  Select one: a. 13.1429 b. 11.0000 c. 12.5714 d. 11.5000

A teacher is interested in assessing whether or not there is the same amount of variance in the scores of a particular type of test between male and female students. She believes that the variance for girls is higher than it is for boys. After grading the test she measures the following:  In her class, 15 boys had a variance of 460 and 13 girls had a variance of 1,400. Set up hypotheses to test if the teacher’s assumption that the girls’ variance of scores on the test is higher than the boys’ variance. Perform the appropriate test and fully state your results.

A factor in determining the usefulness of an examination as a measure of demonstrated ability is the amount of spread that occurs in the grades. If the spread or variation of examination scores is very small, it usually means that the examination was either too hard or too easy. However, if the variance of scores s moderately large, then there is a definite difference in scores between "better," "average," and "poorer" students. A group of attorneys in a midwestern state has been given the task of making up this year's bar examination for the state. The examination has 500 total possible points, and from the history of past examinations, it is known that a standard deviation of around 60 points is desirable. Of course, too large or too small a standard deviation is not good. The attorneys want to test their examination to see how good it is. A preliminary version of the examination (with slight modifications to protect the integrity of the real examination) is given to a random sample…

One of the quality measures in testing is the consistency of the results. The consistency is measured by computing the variance of the results in repeated testing. Two types of blood glucose meter testing kits were tested. Blood from the one vial was used for the testing. Suppose 16 Brand X kits yielded a variance of 2.19 while 25 Brand Y kits yielded a variance of 2.30, Test the claim that the mean blood glucose results are different.