Researchers at a leading university were interested in the effect of sleep on memory consolidation. Twenty-four student volunteers from an introductory psychology course were randomly assigned to...

Researchers at a leading university were interested in the effect of sleep on memory consolidation. Twenty-four student volunteers from an introductory psychology course were randomly assigned to either a “Sleep” or “No-Sleep” group, such that there were 12 students in each group. On the first day, all students were flashed pictures of 15 different objects, for 200 milliseconds each, on a computer screen and asked to remember as many of the objects as possible. That night, the “Sleep” group got an ordinary night’s sleep. The “No-Sleep” group was kept awake until the second night. All subjects got an ordinary night’s sleep on the second and third nights. On the fourth day, all subjects were tested to see how many of the original 15 objects they remembered. The following are the number of objects remembered by each subject on the test:

a. Using??
= 0.052 tail, what do you conclude?

b. Using the confidence-interval approach, construct the 95% confidence interval for??1 –?? 2.

What do you conclude regardingH0? What is your estimate of the size of the effect?

c. Using the confidence-interval approach, construct the 99% confidence interval for?? 1 –?? 2.

What do you conclude regardingH0? What is your estimate of the size of the effect?