<PRE><B>Question 1049760</B>

The average life of a bread making machine is 7 years with a standard deviation of 1 year. assuming that lives of these machines follow approximately a normal distribution. find 
(a) the probability that the mean life of a random sample of such machines fall between 6.4 and 7.2 year?
mean of the sample means = 7
std of the sample means = 1/sqrt(n)
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You have to post the sample size.
Cheers,
Stan H.
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