Boxes of cereal are labeled as containing 14 ounces. Following
are the weights, in ounces, of a sample of 12 boxes: 14.02 13.97
14.11 14.12 14.10 14.02 14.15 13.97 14.05 14.04 14.11 14.12 The
quality control manager is concerned that the mean weight is
actually less than 14 ounces. Your help is needed once again to
construct a confidence interval to estimate the mean weight of all
boxes of cereal of this type. It is reasonable to assume that the
population is approximately normal.
a. Explain why it is not necessary to assess normality for this
sample, even though it is a small sample.
b. Show how to find the boundaries of a 98% confidence interval
using only the highlighted values from your summary statistics
output.
c. Write an interpretation for your confidence interval,
including units if appropriate. You may round the upper and
lower limits to 2 places.
d. Based on the confidence interval, is there a reason the
quality control manager should be concerned that the mean weight is
actually less than 14 ounces? Explain.