Question

7. A study was conducted to investigate the effectiveness of a new drug for treating Stage 4 AIDS patients. A group of AIDS patients was randomly divided into two groups. One group received the new drug; the other group received a placebo. The difference in mean subsequent survival (those with drugs - those without drugs) was found to be 1.04 years and a 95% confidence interval was found to be 1.04 ± 2.37 years. Based upon this information:

Select one or more:

We can conclude that there is evidence the drug was effective because the 95% confidence interval does not cover zero.

We can make no conclusions because we do not know the sample size nor the actual mean survival of each group.

We can conclude that the drug was effective because those taking the drug lived, on average, 1.04 years longer.

We can conclude that there is no evidence the drug was effective because the 95% confidence interval covers zero.

We can conclude that the drug was ineffective because those taking the drug lived, on average, 1.04 years less.

8. A study was conducted to determine the relationship of age and biomarker levels. The age and Prostate-Specific Antigen (PSA) level are measured as continuous data. We could use the following test(s) to analyze the relationship between age and PSA levels:

Select one or more:

Spearman Correlation

Linear regression

Pearson correlation

Chi-square test

Logistic regression

9. The following methods may be used to investigate the association between having nasopharyngeal cancer (yes/no) and consumption of salted fish (yes/no) among 500 adults can be analysed using:

Select one or more:

Pearson correlation coefficient

Logistic regression

Chi-square test

One sample t test

Linear regression

10. According to the logic of hypothesis testing:

Select one or more:

α (alpha) represents the significance level of the test

A type I error occurs when a true null hypothesis is rejected.

A two-tailed test has rejection regions in both tails.

The alternative hypothesis is true if the null hypothesis is false.

If the p value is greater than α , we reject the null hypothesis

11. If a statistical test is significant at the 0.01 level, it is:

Select one:

also significant at the 0.05 level

not significant at the 0.05 level

only significant at the 0.01 level

also significant at the 0.001 level

also significant at the 0.0001 level

Answer 1

Solution:-

7) We can conclude that there is evidence the drug was effective because the 95% confidence interval does not cover zero.

8) Pearson correlation t-test.

9) Chi-square test.

10)

True

α (alpha) represents the significance level of the test

A type I error occurs when a true null hypothesis is rejected.

A two-tailed test has rejection regions in both tails.

The alternative hypothesis is true if the null hypothesis is false.

False:

If the p value is greater than α , we reject the null hypothesis.

11) If a statistical test is significant at the 0.01 level, it is also significant at the 0.05 level.