3) A professor claims that the final exam grades are more widely dispersed in Principles classes compared to upper-level classes. In a sample of 101 Principles final exams, the standard deviation is 16 while in a sample of 30 upper-level class final exams the standard deviation is 13. Test the hypothesis at the 10% level of significance that the 2 variances are different. (15)

Researchers are interested in the effect of pet companionship on depression in elderly adults. They randomly select 25 participants from the target population and record their depression scores before and after spending a month with a dog (a higher score indicates a higher level of depression). The researchers then compute the difference scores for each participant (difference after before). The mean of differences is -1 and the standard deviation of differences is 2. Can the researchers conclude that there is an effect of pet companionship on depression in elderly adults? Conduct the appropriate statistical test (two-tailed) with a = .05. Should you reject or fail to reject the null hypothesis? Reject O Fail to reject

Researchers are interested in the effect of pet companionship on depression in elderly adults. They randomly select 25 participants from the target population and record their depression scores before and after spending a month with a dog (a higher score indicates a higher level of depression). The researchers then compute the difference scores for each participant (difference after before). The mean of differences is - 1 and the standard deviation of differences is 2. Can the researchers conclude that there is an effect of pet companionship on depression in elderly adults? Conduct the appropriate statistical test (two-tailed) with a = .05. Based on the information provided above, which statistical test seems most appropriate? one sample t test O z test independent samples t test O dependent samples t test

Researchers are interested in the effect of pet companionship on depression in elderly adults. They randomly select 25 participants from the target population and record their depression scores before and after spending a month with a dog (a higher score indicates a higher level of depression). The researchers then compute the difference scores for each participant (difference after before). The mean of differences is -1 and the standard deviation of differences is 2. Can the researchers conclude that there is an effect of pet companionship on depression in elderly adults? Conduct the appropriate statistical test (two-tailed) with a = .05. Based on the statistical evidence, can it be claimed that there is an effect of pet companionship on depression in elderly adults? Yes O No

An employer measured the number of units sold by his 400 sales employees. He noted that 40 woman employees had a mean sales of 122 and a variance of 60 while 35 men employees had a mean performance of 126 and a variance of 74. Assuming that the employees were randomly selected and the distribution is normal, is there a reason to believe that there is significant difference between the sales mean performances of the men and women sales employees? Use 0.01 level to test its significance. (Use the two sample mean z-test.)

The main number of English courses taken in a two-year time period by male and female college students is believed to be about the same. An experiment is conducted and data are collected from 29 males and 16 females. This males took an average of three English courses with a standard deviation of 0.8. The females took an average of four English courses with a standard deviation of 1.0. Are the means statistically the same? Assume that the variances are not equal. Test at 5% level of significance. Subscripts: 1: males; 2: females What is the question/claim to be tested in symbols the hypothesis is  Ho: Ha: which hypothesis matches the claim  test objective is to reject or support  level of significance a=.05 type of test (left, right, two-tailed) the applicable test to be applied is           (2-sampZTEST/2-sampTTEST, 2-propZTEST) calculate the applicable test to be applied is (2-sampZTEST/2-sampTTEST, 2-propZTEST) calculate the applicable test statisticz or t= p-value=  compare p-value…

Researchers are interested in the effect of pet companionship on depression in elderly adults. They randomly select 25 participants from the target population and record their depression scores before and after spending a month with a dog (a higher score indicates a higher level of depression). The researchers then compute the difference scores for each participant (difference = after before). The mean of differences is -1 and the standard deviation of differences is 2. Can the researchers conclude that there is an effect of pet companionship on depression in elderly adults? Conduct the appropriate statistical test (two-tailed) with a = .05. Which of the following values is the value of the test statistic in this analysis? O - 2.50 Ⓒ -0.50 - 12.50 - 2.45

Researchers are interested in the effect of pet companionship on depression in elderly adults. They randomly select 25 participants from the target population and record their depression scores before and after spending a month with a dog (a higher score indicates a higher level of depression). The researchers then compute the difference scores for each participant (difference = after before). The mean of differences is -1 and the standard deviation of differences is 2. Can the researchers conclude that there is an effect of pet companionship on depression in elderly adults? Conduct the appropriate statistical test (two-tailed) with a = .05. The 95% Confidence Interval for the population parameter is: [-6.16, 4.16] [-3.50, 1.50] [-1.83,-.17] [-3.06, 1.06]

Researchers are interested in the effect of pet companionship on depression in elderly adults. They randomly select 25 participants from the target population and record their depression scores before and after spending a month with a dog (a higher score indicates a higher level of depression). The researchers then compute the difference scores for each participant (difference = after before). The mean of differences is -1 and the standard deviation of differences is 2. Can the researchers conclude that there is an effect of pet companionship on depression in elderly adults? Conduct the appropriate statistical test (two-tailed) with a = .05. Select the null hypothesis for this statistical analysis. HD=0 HD = -1 =0 H1-H2 = -1

Researchers are interested in the effect of pet companionship on depression in elderly adults. They randomly select 25 participants from the target population and record their depression scores before and after spending a month with a dog (a higher score indicates a higher level of depression). The researchers then compute the difference scores for each participant (difference = after before). The mean of differences is -1 and the standard deviation of differences is 2. Can the researchers conclude that there is an effect of pet companionship on depression in elderly adults? Conduct the appropriate statistical test (two-tailed) with a = .05. Which of the following values are the critical values in the analysis? 12.060| O 12.0691 11.960| 12.0641