SOLUTION: The average diameter of certain Euro coins 3.00 millimeters with a standard deviation of 0.70 millimeters. If 9 coins are chosen at random, find the probability that the average

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Question 427624: The average diameter of certain Euro coins 3.00 millimeters with a standard deviation of
0.70 millimeters. If 9 coins are chosen at random, find the probability that the average
diameter of those coins is more than 2.790 millimeters. Assume that the variable is
normally distributed.
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!


Hi

Note: z+=blue+%28x+-+mu%29%2Fblue%28sigma%2Fsqrt%28n%29%29

 z = (2.79-3.00) / .7/3 = -.21 *3/.7 = -.9

P(z > -.9) =  probability that the average diameter is more than 2.790mm