Bags of a certain brand of potato chips say that the net weight of the contents is 35.6 grams. Assume that the standard deviation of the individual bag weights is 5.2 grams.
A quality control engineer selects a random sample of 100 bags. The mean weight of these 100 bags turns out to be 33.6 grams.
Does the sample provide strong evidence that the mean weight of the bags is lower than the 35.6 grams listed on the package?
a)Yes, because a random sample of 100 bags with a mean weight below 33.6 grams is very unlikely if the individual bags have a mean weight of 35.6 grams.
b) No, because random samples of 100 bags will have mean weights that vary. A mean weight of around 33.6 grams is not unusual.
c) No, because the mean weight of the sample is only off by 2 grams.
d) Yes, because 33.6 is less than 35.6 grams.