Question

david is a statistician. he has a sample size of 40 (which he cannot change). what element of his hypothesis test can he adjust to minimize the probability that he incorrectly rejects the null hypothesis?

o the mean of the population

o the mean of the sample

o the standard deviation of the population

o the significance level of the test

Explanation:

The probability of incorrectly rejecting the null hypothesis is the Type - I error rate, which is equal to the significance level ($\alpha$) of the test. By reducing the significance level, we can minimize this probability. The mean of the population and sample, and the standard deviation of the population are not directly adjustable to control this specific error probability when the sample size is fixed.

Answer:

the significance level of the test