Question 5

Which of the following statements is the best interpretation of the 95% confidence interval for the mean?

Select one:

a. If repeated samples were taken and the 95% confidence interval was computed for each sample, 95% of all possible random samples will result in an interval that contains the true population mean.

b. The probability that the true mean of the population is contained within the confidence interval is roughly 95%.

c. A range that contains 95% of the values of the population distribution.

Question 6

In a past APS Compass for Life Wellbeing Survey, a random sample of Australian school children answered the question "Are you a member of any sports clubs?" Based on the sample data, 95% confidence intervals for the population proportion who would answer "yes" are .13 to .19 for girls and .247 to .33 for boys. Based on these results, we can reasonably conclude that:

Select one:

a. At least 25% of Australian girls and boys belong to sports clubs.

b. At least 16% of Australian girls belong to sports clubs.

c. There is a difference between the proportions of Australian girls and boys who belong to sports clubs.

d. There is no conclusive evidence of a gender difference in the proportion belonging to sports clubs.

Question 7

In a study to determine whether prior treatment for hyperthyroid conditions is associated with subsequent development of Parkinson's disease, the estimated relative risk for those with prior treatment for hyperthyroid conditions compared to those who had not had treatment for hyperthyroid conditions was found to be 1.9 (95%CI: 1.2-2.5). From this we can conclude:

Select one:

a. The case fatality rate is higher among patients who have had a prior treatment for hyperthyroid conditions

b. The incidence of Parkinson's disease is higher among those who have had a prior treatment for hyperthyroid conditions

c. Treatment for hyperthyroid conditions appears to protect against the development of Parkinson's disease

d. Treatment for hyperthyroid conditions should not be used because it increases the risk of Parkinson's disease

e. We cannot draw any conclusions from these data

Question 8

The pesticide DDT causes tremors and convulsions if it is ingested by humans or other mammals. Researchers seek to understand how the convulsions are caused. In a randomized comparative experiment, 6 white rats poisoned with DDT were compared with a control group of 6 unpoisoned rats. Electrical measurements of nerve activity are the main clue to the nature of DDT poisoning. When a nerve is stimulated, its electrical response shows a sharp spike followed by a much smaller second spike. Researchers found that the second spike is large in rat fed DDT than in normal rats. This observation helps biologists understand how DDT causes tremors.

The researchers measured the amplitude of the second spike as a percentage of the first spike when a nerve in the rat's leg was stimulated. For the poisoned rats the results were

20.589; 12.207; 16.869; 25.050; 22.429; 18.456

The control group data were

5.642; 11.074; 9.686; 13.064; 9.351; 8.182

Use a test with a 5% level of significance to confirm that there is a real effect. State hypothesis; test used with reason; and interpret the outcome with reference to appropriate values from the output.

Question 9

Which following sets has an IQR value that is 8?

Select one:

a.12, 5;19;15;13;14;18, 6;7;13;15;6;7

b.13;13;12, 19;14;5;7;11th;6;15;19;7;13

c.15, 13;5;16;11;8;6;13;7;13: 7;19;14

d.8;14;13;15;11, 13;18, 11;6;7;15;7;5

e 19;13;15;7;14;5;12;13;13;5, 11: 18;11