
A First Course in Probability (10th Edition)
10th Edition
ISBN: 9780134753119
Author: Sheldon Ross
Publisher: PEARSON
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Question
Rockwell hardness of pins of a certain type is known to have a
(a) If the distribution is normal, what is the probability that the sample mean hardness for a random sample of 18 pins is at least 51?
(b) What is the (approximate) probability that the sample mean hardness for a random sample of 45 pins is at least 51?
(b) What is the (approximate) probability that the sample mean hardness for a random sample of 45 pins is at least 51?
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