Question

You are interested in whether a study intervention significantly affects students’ grades on a statistics final exam. You recruit a random sample of 25 students. Across all sections of statistics, students have a final exam µ = 76. You choose an alpha level of .05 and decide to perform a two-tailed test. What would be the correct way to write out the null hypothesis (H₀) that you are testing?

a) H₀: μ ≠ 76

b) H₀: μ = 76

c) H₀: μ > 76

d) H₀: μ < 76

Answer 1

The null hypothesis for a two-tailed test where the aim is to determine the effect of an intervention on exam scores is H₀: μ = 76, which suggests no significant change from the population mean.

Step-by-step explanation:

The correct way to write out the null hypothesis (H₀) that you are testing for a two-tailed test where you want to determine if a study intervention significantly affects students’ grades on a statistics final exam is:

b) H₀: μ = 76

This denotes that there is no significant difference in the mean score from the general population mean score of 76, which is what the null hypothesis asserts in a two-tailed test. A two-tailed test is appropriate in this scenario because the research does not specify a direction of change; you are testing for any significant difference, either increase or decrease, from the assumed mean of 76.