In a random sample of 13 microwave ovens, the mean repair cost was $85.00 and the standard deviation was $15.30. using the standard normal distribution with the appropriate calculations for a standard deviation that is known, assume the population is normally distributed, find the margin of error and construct a 95% confidence interval for the population mean. a 95% confidence interval using the t-distribution was (75.8, 94.2 ). compare the results.

Margin of error = 8.32, and Confidence interval using normal distribution is narrower than confidence interval using t-distribution.

Step-by-step explanation:

Since we have given that

n = 13

Mean repair cost = $85.00

Standard deviation = $15.30

At 95% confidence interval,

z= 1.96

Since it is normally distributed.

Margin of error is given by

95% confidence interval would be

A 95% confidence interval using the t-distribution was (75.8, 94.2 ).

Confidence interval using normal distribution is narrower than confidence interval using t-distribution.

10

step-by-step explanation:

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