Question

A bolt manufacturer is very concerned about the consistency with which his machines produce bolts. The bolts should be 0.210.21 centimeters in diameter. The variance of the bolts should be 0.0250.025. A random sample of 2525 bolts has an average diameter of 0.2cm0.2⁢cm with a standard deviation of 0.05450.0545. Can the manufacturer conclude that the bolts vary from the required variance at α=0.05α=0.05 level?

Step 1 of 5:

State the hypotheses in terms of the standard deviation. Round the standard deviation to four decimal places when necessary. Ho:_____________Ha:_____________

Step 2 of 5:

Determine the critical value(s) of the test statistic. If the test is two-tailed, separate the values with a comma. Round your answer to three decimal places.

Step 3 of 5:

Determine the value of the test statistic. Round your answer to three decimal places.

Step 4 of 5:

Make the decision.

a. Reject Null Hypothesis

b. Fail to Reject Null Hypothesis

Step 5 of 5:

What is the conclusion?

a. There is sufficient evidence that shows the bolts vary by more than the required variance.

b. There is not sufficient evidence that shows the bolts vary by more than the required variance.

Answer 1