Question

1.I am taking samples of size n from a normal distr-ibution with a mean of 1. I then do a hypothesis test of whether the mean is equal to 0. What will happen to the p-value as i take more samples? (a) It will increase (b) It will decrease (c) Not enough information.

2. I am doing a chi-squared test of independence. What will happen to the p-value if my degrees of freedom increase? (a) It will increase (b) It will decrease (c) Not enough information.

3. A point that is above the linear regressio-n line : (a) Must have a positive residual (b) Must have a negative residual (c) Is an outlier (d) Cannot be determined

4. Ketamine is a type of medication that can be used to prevent a seizure. Data was collected from 100 patients who were treated with varying doses of ketamine and the time till their next seizure was measured. The average dose of ketamine was 100 micrograms with a standsrd deviation of 25. The average time till seizure was 612 minutes with a standard deviation of 200 minutes. The correlation between these two variables is 0.72. What is the equation for the regression line where X is ketamin dose in micrograms?

(a) Y = 36 + 5.76X (b) Y = 36 + 0.125X (c) Y = −3425 + 5.76X (d) Y = −3425 + 0.125X

Answer 1

1. As sample size increases absolute value of test statistic decreases and then p-value increases.

Option: (a) It will increase

2. We know chi square distribution is positively skewed and as n tends to infinity the shape of this distribution tends to symmetric and using central limit theorem we approximate its distribution by normal distribution. Moreover p-value is the probability of obtaining results as extreme as the observed results of a statistical hypothesis test, assuming that the null hypothesis is true so as n increases p-value increases so

Option: (a) It will increase

3. Option (d) Cannot be determined

4.