1. A paired t-test is appropriate for comparing which of the following?

1. A variable in two samples matched on age and sex.
2. Two continuous variables from a single sample.
3. Weight loss in people from Ottawa vs Toronto who adopted the same keto diet.
4. Dependent variables sampled from a non-normal population.

2. Researchers want to compare the concentrations of two types of drugs (A & B) in urine specimens taken from the same person 1 hour after he/she has taken the drug. A dosage of either type A or type B of the drug is given at one time and the 1-hour urine concentration is measured (in mg%). One week later, after the first drug has been cleaned from the system, the same dosage of the other drug is given to the same person and the 1-hour urine concentration is noted. The study is performed on 10 people. The mean concentration levels of types A and B of the drug 1-hour after ingestion were 19.20 and 15.60, respectively. The statistical test was done assuming =0.01 and concentration levels were normally distributed with unknown and equal variances. What degrees of freedom and critical value should be used in the statistical test?

1. 9 and +/- 3.250

1. 18 and +/-2.878
2. 9 and +/- 2.262
3. 18 and +/- 2.101

3. Researchers wanted to know if cognitive screening should be used to help select appropriate candidates for a diabetes self management program for older adults. They studied a sample of 19 geriatric patients who took the program and obtained their scores on the Mini Mental State Examination (MMSE) at admission and discharge. The researchers conducted the appropriate statistical test to test the null hypothesis of no difference in the admission and discharge MMSE scores for the 19 patients. MMSE scores in geriatric patients are known to be normally distributed with known variance. What degrees of freedom apply to the critical value used in the statistical test?

1. 18
2. 17
3. 36
4. Degrees of freedom do not apply in this case.

4. The average cholesterol reduction (in mg) for two cholesterol-reducing drug regimens (A and B) were compared in two different patient samples. Random samples of 30 patients were obtained from two family health teams (FHTs) in Hamilton, one used drug A and the other used drug B. Choose the appropriate parameter(s) for the hypotheses used in the statistical test to compare the average cholesterol reduction for the two drugs.

1. One population proportion
2. Difference between two population means
3. One population mean
4. Difference between two population proportions

1. Suppose you would like to determine if the mean wait time (in days) for 3 patient groups differs depending on the type of surgical procedure performed. You have data from 9 patients that underwent gall bladder removal, 8 patients that underwent hip replacement, and 11 patients that underwent knee replacement surgery. Assume that the populations are normally distributed with equal variances. Having chosen the appropriate statistical test to answer this question (alpha = 0.05), what are the degrees of freedom and critical value for the test statistic?

1. 3, 28, 8.62
2. 2, 25, 3.39
3. 3, 25, 8.63
4. 26, 2.056

5. When computing an ANOVA statistic, the sum of squares error (SSE) term measures the variability of:

1. The individual group means around the grand mean
2. The individual observations around their respective group mean
3. The individual observations around the grand mean
4. The between compared to the within group differences

6. When computing an ANOVA statistic, if the degrees of freedom for the total sum of squares is 47, and the number of groups being compared is 4, what is the total sample size?

1. 3
2. 44
3. 47
4. 48