# Question

The weights of full boxes of a certain kind of cereal are normally distributed with a standard deviation of 0.27 oz. A sample of 18 randomly selected boxes produced a mean weight of 9.87 oz.

a. Find the 95% confidence interval for the true mean weight of a box of this cereal.

b. Find the 99% confidence interval for the true mean weight of a box of this cereal.

c. What effect did the increase in the level of confidence have on the width of the confidence interval?

a. Find the 95% confidence interval for the true mean weight of a box of this cereal.

b. Find the 99% confidence interval for the true mean weight of a box of this cereal.

c. What effect did the increase in the level of confidence have on the width of the confidence interval?

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