The average monthly electric bill of a random sample of 256 residents of a city is $111 with a standard deviation of $32.

a.
Construct a 90% confidence interval for the mean monthly electric bills of all residents.
b.
Construct a 95% confidence interval for the mean monthly electric bills of all residents.

Question

The average monthly electric bill of a random sample of 256 residents of a city is $111 with a standard deviation of $32.
​
a.
Construct a 90% confidence interval for the mean monthly electric bills of all residents.
b.
Construct a 95% confidence interval for the mean monthly electric bills of all residents.

Quizplus · Accepted Answer

The Answer of The average monthly electric bill of a random sample of 256 residents of a city is $111 with a standard deviation of $32.
​
a.
Construct a 90% confidence interval for the mean monthly electric bills of all residents.
b.
Construct a 95% confidence interval for the mean monthly electric bills of all residents.

The Average Monthly Electric Bill of a Random Sample of 256