Question

Question 7

The mean monthly rent for a one-bedroom apartment without a doorman in Manhattan is $ 2,642 . Assume the standard deviation is $500. A real estate firm samples 100 apartments. What is the probability that the average rent of the sample is more than $ 2,710 ?

Write only a number as your answer. Round to 4 decimal places (for example 0.1048). Do not write as a percentage.

Question 8

A survey among freshmen at a certain university revealed that the number of hours spent studying the week before final exams was normally distributed with mean 25 and standard deviation 15. A sample of 36 students was selected. What is the probability that the average time spent studying for the sample was between 26.7 and 30 hours studying?

Write only a number as your answer. Round to 4 decimal places (for example 0.0048). Do not write as a percentage.

Question 9

Electricity bills in a certain city have mean $ 122.40 . Assume the bills are normally distributed with standard deviation $ 13.54 . A sample of 73 bills was selected for an audit. Find the 58 percentile for the sample mean.

Write only a number as your answer. Round to two decimal places (for example: 42.81). Do not write any units.

Answer 1

TOPIC:Sampling distribution of the sample mean and the required probabilities.