Question 437771
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Hi
*Note: {{{z =(X - mu)/(sigma/sqrt(n))}}}
In a study of the time college freshmen use to study each week,
mean is 6.8 hours with a standard deviation of 2.5 hours
Sample size n = 100 Find: P(X > 7hr)   
 z = (7-6.8)/(2.5/10) = .2/.25 = .8
P(z >.8) = 1 - .7881 = .2119