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

a) 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:

b) In a study of jury behavior, two samples of participants were given details about a trial in which the defendant was obviously guilty. Although group 2 received the same details as group 1, the second group was also told that some evidence had been withheld from the jury by the judge. Later the participants were asked to recommend a jail sentence. We are interested in whether the length of the jail sentence was significant between the two samples?

Is this a one- or two-tailed test?

H₀:

H₁: