use the normal distribution of SAT critical reading scores f

use the normal distribution of SAT critical reading scores for which the mean is 512 and the standard deviation is 122. assume the variable x is normally distributed. a) If 1000 SAT verbal scores are randomly selected, about ho many would you expect to be greater than 550?

Solution

use the normal distribution of SAT critical reading scores for which the mean is 512 and the standard deviation is 122. assume the variable x is normally distributed. a) If 1000 SAT verbal scores are randomly selected, about how many would you expect to be greater than 550?

Z value for 550, z=(550-512)/122 =0.31

P( x >550) = P(z >0.31) = 0.3783

0.3783*1000=378.3

There are 378 scores are more than 550.