Question

1. State the null hypothesis and the alternative hypothesis for each of the following examples.

After low scores on the first exam, a chemistry teacher wants to boost her students’ long-term retention of the material so she introduces them to a new study technique to see if it improves their memory for the material. She wants to see whether her class’ Exam 2 scores are significantly higher than their Exam 1 scores.

Is this a one- or two-tailed test? H0: H1:

Answer 1

Since we want to know whether eam 2 scores are higher than exam 1 scores ( or in other words if exam 1 scores are lesser than exam 2 scores)

The Null Hypothesis: H0:

The Alternate Hypothesis: Ha:

This is a one tailed test.

_____________________________________________

If exam 2 score is taken first then the null hypothesis would remain the same,

H0:

Ha:

Since it is not mentioned who should be taken as the first score, both the hypothesis will work. Both are one tailed hypothesis. In case 1, we take the critical value and p value for a one tailed, left tailed test, whereas in Case 2, we take the critical value and p value for a one tailed, right tailed test.