(b) we often read that iq scores for large populations are centered at 100. what percent of these 78 students have scores above 100? (round your answer to one decimal place.)

Respuesta :

As IQ scores for extensive populaces are focused at 100, the mean = 100. 
There ought to be around half scores above or underneath the mean score since mean and middle is about a similar when the populace is substantial. 
P(x > 100) = P( z> (100 - 100)/sd ) = P(z > 0)= 0.5 
The number of the student who has scored over 100 = 0.5 x 78 = 39 Therefore the answer is 39 students.