The average mark (out of 100) of a class of 300 students on a statistics examination is 68.2 with standard deviation 9.2. Suppose random sample of marks of 40 students is selected. What is the probability that the sample mean will be (a) less than 65? (b) more than 72?

The average mark (out of 100) of a class of 300 students on a statistics examination is 68.2 with standard deviation 9.2. Suppose random sample of marks of 40 students is selected. What is the probability that the sample mean will be (a) less than 65? (b) more than 72?

A First Course in Probability (10th Edition)

10th Edition

ISBN:9780134753119

Author:Sheldon Ross

Publisher:Sheldon Ross

Chapter1: Combinatorial Analysis

Section: Chapter Questions

Problem 1.1P: a. How many different 7-place license plates are possible if the first 2 places are for letters and...

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Question

The average mark (out of 100) of a class of 300 students on a statistics examination is 68.2 with
standard deviation 9.2. Suppose random sample of marks of 40 students is selected. What is the probability that
the sample mean will be
(a) less than 65?
(b) more than 72?

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