Question

Dole pineapple, Inc., is concerned that the 15-ounce can of sliced pineapple
is being overfilled. Assume the standard deviation of the process is 0.03
ounces.

The quality-control department took a random sample of 40 cans and found
that the arithmetic mean weight was 15.01 ounces.

At the 5 percent level of significance, can we conclude that there is a change
in the mean weight? Please determine the p-value as well.

Answer 1

The null and alternative hypothesis is ,

The test is two-tailed test.

Now , the population standard deviation is know,

Therefore, use normal distribution.

The critical value is ,

; From Z-table

The test statistic is ,

Decision : Here , the value of the test statistic lies in the rejection region.

Therefore , reject Ho.

Conclusion : Hence , there is sufficient evidence to conclude that the there is change in the mean weight.

The p-value is ,

p-value =

; The Excel function is , =2*(1-NORMDIST(2.11,0,1,TRUE))