Module 7 Discussion: Confidence Intervals

In this module we continue exploring the topic of confidence intervals, one of the most frequently misunderstood concepts in Statistics. Please, read, answer and comment on the questions below.

At the time of presidential elections, we're hearing many poll results, with many of them also reporting their margins of error. What does margin of error tell us and why is it important, particularly, for polls?

What role does a Sample size play in the calculation of confidence intervals? Describe the roles Sample size, Confidence Level and Margin of Error play in the width of the confidence interval.

The clothing buyer for a chain of department stores wants to be sure the store orders the right mix of sizes for its male customers. She conducts a survey of the heights of men who visit their store, selects a Sample of 50 answers, and constructs a 95%Confidence Interval. The interval she obtains is (68.2 in., 73.9 in.). Select the correct interpretation of the result:

The clothing buyer is ...

a) 95%confident that the probability the mean height of men who visit their store lies between about 68.2 and 73.9 inches.

b) 95%confident that the mean height of men who visit this store lies between about 68.2 and 73.9 inches.

c) 95%confident that the mean height of men who visit this store does not lie between 68.2 and 73.9 inches.

Instructions:

Your initial post approximately 200-250 words