Exercise on the Z Confidence Interval for the Population Mean
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Estimate the mean price of all tickets with 81% confidence. After collecting a random sample of 38 tickets you find a sample mean of 79 dollars. Assume the distribution of price for all tickets is normal with a standard deviation of 5.3 dollars.
Directions: Fill in the blanks and click the button to have your answers graded.
A. Do not round intermediate calculations.
B. Round your answers to two decimal places.
C. You have 30 minutes to complete your work before session timeout. After that your work
will not be graded correctly.
1. Z table value =
2. Margin of Error =
3: You estimate with 81% confidence that the population mean falls between
the lower value of
and the upper value of
(If you get Question 3 correct, you will be asked an additional question)
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