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A psychologist believes that students’ test scores will be affected if they have too much caffeine...

A psychologist believes that students’ test scores will be affected if they have too much caffeine before taking an exam. To examine this, she has a sample of n = 15 students drink five cups of coffee before taking an exam. She uses an exam that has a population mean of µ = 72 and a population standard deviation s = 3. The mean test score for the sample of 15 students who drank five cups of coffee before taking the exam was M = 69. Do a t-test using a = .01 a. Is this a one-tailed test or a two-tailed test? (circle one) b. What is the research hypothesis, H1? c. What is the null hypothesis, H0? d. Calculate the degrees of freedom (df) for this problem. e. From the t-distribution table (B.2), what is the critical value of tcrit for a = .01? f. Calculate the mean of the distribution of sample means, µM g. Calculate the standard error of the mean, sM h. Calculate the t-score of the sample mean. i. Sketch the distribution of sample means. Indicate where the sample mean is, where the critical value of t is, and the area under the tail of the curve. j. Can you reject the null hypothesis, H0? YES or NO (circle one) k. Can you accept the research hypothesis, H1? YES or NO (circle one)

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