Question

Hypothesis Tests for Population Means when the Standard Deviation is known for each of the following situations complete the steps listed below.

a. State the Alternative and null Hypotheses. b. State the Level of Significance c. Calculate the Test Statistic. d. Draw a conclusion by comparing the p-value to the level of significance.

A manufacturer must test that his bolts are 2.00 cm long when they come off the assembly line. He must recalibrate his machine if the bolts are too long or too short. After sampling 100 randomly selected bolts off of the assembly line, he finds that the sample mean is 1.90 cm. He knows that the population standard deviation is 0.50 cm. Assuming a level of significance of .05, is there sufficient evidence to show that the manufacturer needs to recalibrate the machines?

Answer 1