Question: A potato chip manufacturing manager who is interested in quality control wants to learn if the potato chip bag filling process is under control, i.e., remains at the specified amount. The specified fill is 358 grams. To ascertain this, the manager takes a random sample of 30 bags, weighs each one and then computes a mean for the sample, 329. He then evaluates the difference between the sample mean of 329 and the hypothesized population mean (the specified fill of 358). Assume the population standard deviation is known and is 10. Do a z-test:

(to calculate the standard error you need to divide the population standard deviation by the square root of N. ) YOU DO NOT HAVE TO USE EXCEL.

Choose a significance level of .01.

Reject Ho if your z is greater than + or – 2.58.

Explain your conclusions.

(IF THE POPULATION STANDARD DEVIATION WAS NOT KNOWN, YOU WOULD HAVE TO DO A ONE SAMPLE T – TEST)