In: Statistics and Probability
The Intelligence Quotient (IQ) test scores are normally distributed with a mean of 100 and a standard deviation of 15 What is the probability that a person would score between 85 and 115?
Solution :
Given that ,
mean = = 100
standard deviation = =15
P(85< x <115 ) = P[(85-100) / 15< (x - ) / < (115-100) / 15)]
= P(-1 < Z <1 )
= P(Z <1 ) - P(Z <-1 )
Using z table
= 0.8413-0.1587
probability= 0.6826