A camp director is interested in the mean number of letters each child sends during his or her camp session. The population standard deviation is known to be 2.5. A survey of 20 campers is taken. The mean from the sample is 7.9 with a sample standard deviation of 2.8.
A camp director is interested in the mean number of letters each child sends during his or her camp session. The population standard deviation is known to be 2.5. A survey of 20 campers is taken. The mean from the sample is 7.9 with a sample standard deviation of 2.8.
(b). Define the random variables X and Xbar in words.
Soln.
(c). What distribution should be used for this problem? Explain your choice.
Soln.
(d). Construct a 90% confidence interval for the population mean number of letters campers sent home and interpret your results in the context of the question.
Soln.
(e). What will happen to the margin of error and confidence interval if 500 campers are surveyed? and why?
Soln.
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