Question 1044807: Use the normal distribution of SAT critical reading scores for which the mean is 501 and the standard deviation is 113. Assume the variable x is normally distributed.
a) What percent of the SAT scores are less than 675? Round to two decimal places as needed.
b) You would expect that approximately how many SAT scores would be greater than 550? Round to the nearest whole number.
Answer by Boreal(15235)   (Show Source):
You can put this solution on YOUR website! z=(x-mean)/sd
=(675-501)/113
=1.54
want probability z < 1.54=0.9382 or 93.82%.
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z=(550-501)/113=49/113=0.43
probability z > 0.43 is 0.334
I can't say how many SAT scores would be greater than 550, only the per cent, which is 33.36%, very close to one third, and 33% to the nearest whole number.
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