Question

In: Statistics and Probability

A random sample of 2020 purchases showed the amounts in the table​ (in $). The mean...

A random sample of

2020

purchases showed the amounts in the table​ (in $). The mean is

​$49.8149.81

and the standard deviation is

​$21.9521.95.

​a) Construct a

8080​%

confidence interval for the mean purchases of all​ customers, assuming that the assumptions and conditions for the confidence interval have been met.

​b) How large is the margin of​ error?

​c) How would the confidence interval change if you had assumed that the standard deviation was known to be

​$2222​?

A) The new confidence interval ( _ , _) is wider than the interval from part a.

OR

B.The new confidence interval ( _ , _) is narrower than the interval from part a.

Solutions

Expert Solution

orchestra answered 1 year ago
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