1. For a random sample, X = 83 and n = 625; assume ø = 15.
a. Test H0: µ = 80 against H1: ≠ 80 (œ = .05). What does this tell you about µ?
b. Construct the 95% confidence interval for µ. What does this tell you about µ?
c. Which approach gives you the more information about µ? (Explain).
2. From Table B, identify the value t for that df = 15.
a. is so high that only 1% of the t values would be higher
b. is so low that only 10% of the t values would be lower.
3. The task in particular concept-formation experiment is to discover, through trial and error, the correct sequence in which to press a row of buttons. It is determined from the nature of the task that the average score obtained by random guessing alone would be 10 correct out of a standard series of trials. The following are the scores for a sample of volunteer college students: 31, 24, 21, 25, 32. You wish to determine whether such subjects do better, on the average, than expected by just guessing.
a. Set up H0 and H1.
b. Determine t. 05.
c. Perform the statistical test
d. Draw final conclusions.