SOLUTION: 78% of U.S. Homes have a telephone answering device. In a random sample of 234 homes, what is the probability that fewer than 42 do not have a telephone answering device? Round z v
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Question 1081888: 78% of U.S. Homes have a telephone answering device. In a random sample of 234 homes, what is the probability that fewer than 42 do not have a telephone answering device? Round z value calculations to 2 decimal places and final answer to 4 decimal places.
P (X < 42) Answer by Boreal(15235) (Show Source):
You can put this solution on YOUR website! mean is 234*.78=182.52
variance is 234*.78*.22=40.1544
sqrt (V)=sd=6.34
number of homes that don't is 51.48
z<(41.5-51.48)/6.34=-1.56
That probability is 0.0588.
