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Rockwell hardness of pins of a certain type is known to have a mean value of 50 and a standard deviation of 1.6. (Round

Posted: Mon Nov 15, 2021 12:31 pm
by answerhappygod
Rockwell hardness of pins of a certain type is known to have a
mean value of 50 and a standard deviation of 1.6. (Round your
answers to four decimal places.)
(a) If the distribution is normal, what is the probability that
the sample mean hardness for a random sample of 12 pins is at least
51?