The Average Monthly Electric Bill of a Random Sample of 256

question 20

Short Answer

The average monthly electric bill of a random sample of 256 residents of a city is $90 with a standard deviation of $24.
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.

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Definitions:

Outcome

The result or consequence of an experiment, action, or occurrence.

Prior Probabilities

Initial estimates of the probabilities of events.

Probabilities

The assessment of the probability that a particular event will take place.

Combinations

A method of counting that determines the number of possible arrangements in a collection without regard to the order of the elements.