Question

JUSTIN SHORT Question 6 of 13 Step 1 of S 01:58:05 A bolt manufacturer is very concerned about the consistency with which his machines produce bolts. The bolts should be 0.24 centimeters in diameter. The variance of the bolts should be 0.015. A random sample of 12 bolts has an average diameter of 0.23 cm with a standard deviation of 0.0642. Can the manufacturer conclude that the bolts vary by less than the required variance at a = 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. Tables Keypad Answer 2 Points Но H stTakeTest #! IMG-2112JPG IMG-2113JPG IMG-2114JPG

Answer 1

Solution:

This is a left (One) tailed test,

The null and alternative hypothesis is,  

Ho: $\sigma ^{2}$ $\geq$ 0.015

Ha: $\sigma ^{2}$ 0.015