Question

Is sleep or caffeine better for memory? To answer this question, 24 randomly chosen adults
were divided equally into two groups and given a list of 24 words to memorize. During a break,
members of one group took a 90-minute nap while members of the other group each took a
caffeine pill. They were then all tested to see how many of the words they could remember; the
results are available on StatKey as the Sleep Caffeine Words dataset.
(a) Use StatKey to create a relevant bootstrap distribution, then use that distribution to
obtain a relevant 95% confidence interval.
(b) State the relevant null and alternative hypotheses.
(c) Use StatKey to create a randomization distribution based on this data and H0, then
determine the p-value and state your conclusion clearly.

Answer 1

(a) The 95% confidence interval is between -0.128 and -0.012.

(b) The hypothesis being tested is:

H₀: µ₁ = µ₂

H₁: µ₁ ≠ µ₂

(c) The Statkey output is:

The p-value is 0.026.

Since the p-value (0.026) is less than the significance level (0.05), we can reject the null hypothesis.

Therefore, we can conclude that there is a different effect of sleep or caffeine for memory.