Statistics
posted by Rebecca .
The mean television viewing time for Americans is 15 hours per week. Suppose a sample of 60 Americans is taken to further investigate viewing habits. Assume the population standard deviation for weekly viewing ime is o = 4 hours.
A What is the probability the sample mean will be within 1 hour of the population mean?
B. What is the probability the sample mean will be within 45 minutes of the population mean?

You need to convert the hours to a Z score and then look up the probabilities in the back of your statistics textbook in an appendix labeled something like "areas under the normal distribution."
Z = (X  ƒÊ)/SD, where X = raw score, ƒÊ = mean and SD = standard deviation.
A involves X of 14 to 16, while B involves X of 14.25 to 15.75, converting minutes to portions of an hour.
You should be able to solve it with this information. I hope it helps. Thanks for asking. 
Just wanted to say thank you for your help. It is greatly appreciated.

kjjn

0.38680

NO IDEA PLZ HELP ME
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