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2021-03-11

The local energy company claims the average annual electricity bill for its subscribers is just $600. A consumer watchdog group wants to dispute this claim. All agree that the standard deviation sigma of annual electricity bills is $150.

Some time later, a wealthy activist provides funding for a simple random sample of 250 households. The average annual electricity bill for this sample is $622. Find a$95\mathrm{\%}$ confidence interval for the true mean annual electric bill, based on this sample.

Some time later, a wealthy activist provides funding for a simple random sample of 250 households. The average annual electricity bill for this sample is $622. Find a

Demi-Leigh Barrera

Skilled2021-03-12Added 97 answers

Step 1

It is assumed that the sample mean is 622 and the population standard deviation is 150.

Step 2

From the given information, the confidence level is 0.95 and the level of of significance

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