Question

The distribution of a particular IQ test scores for persons over 16 years of age is approximately Normal with mean 100 and standard deviation 17.

What is the probability that the average IQ score of an SRS of 60 people is 104 or higher? (Round your answer to four decimal places.)

Answer 1

Solution :

Given that ,

mean = = 100

standard deviation = = 17

n = 60

= 100

= / n =17 / 60 = 2.19

P( >104 ) = 1 - P( < 104)

= 1 - P[( - ) / < (104-100) / 2.19]

= 1 - P(z < 1.83)

Using z table

= 1 - 0.9664

= 0.0336

probability= 0.0336