a) The college bookstore tells prospective students that the average cost of its textbooks is $52. A group of smart statistics students thinks that the average cost is higher. In order to test the bookstore’s claim, the students will select a random sample of size 100. Assume that the mean from their random sample is $52.80 with a standard deviation of $4.50. Perform a hypothesis test at the 5% level of significance and state your decision. b) A manufacturing process produces 0.5 cm ball bearings with diameters that have a normal distribution. Ball bearings with diameters that are too small or too large are undesirable. Assume that a random sample of 25 gave a mean diameter of 0.51 centimeters with a standard deviation of .04 cm. Is this enough evidence to suggest that the mean diameter of the ball bearings is not 0.5 centimeters (as advertised)? Use the 0.05 level of significance.
1. Use Minitab to run each hypothesis test. Give careful thought about whether to run a z-test or a t-test. Report the null and alternative hypothesis, the p-value, and the interpretation of the p-value using everyday language.
a) The college bookstore tells prospective students that the average cost of its textbooks is $52. A group of smart statistics students thinks that the average cost is higher. In order to test the bookstore’s claim, the students will select a random
b) A manufacturing process produces 0.5 cm ball bearings with diameters that have a
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