The sugar content of syrup in canned peaches is normally distributed, and variance is thought to be s2 = 18 (mg)2.
a. Test the hypothesis that variance is not 18 (mg)2 if random sample of n=10 cans yields sample standard deviation of s=4 mg, using a fixed-level test with a=0.05. State any necessary assumptions regarding the underlying distribution of data.
b. Determine the P-value for this test?
c. Determine a 95% two-sided CI for s.
d. Employ the CI in part c) to test the hypothesis.