A bolt manufacturer is very concerned about the consistency with which his machines produce bolts. The bolts should be 0.15 centimeters in diameter. The variance of the bolts should be 0.025. A random sample of 23 bolts has an average diameter of 0.14cm with a standard deviation of 0.2627. Can the manufacturer conclude that the bolts vary by more than required variance at a = 0.01 level?

1. state the hypotheses in terms of the standard deviation. Round the standard deviation to 4 decimal places when necessary.

Ho:________ Ha:____________

2. Determine the critical value of test statistic. If the test is two-tailed, separate the value with a comma, round 3 decimal places.

3. Determine the value of the test statistic, Round 3 decimal places

4. Make the decision

choose either reject null hypothesis or fail to reject null hypothesis

5. what is the conclusion?

choose either there is sufficient evidence or there is not sufficient evidence