Question

The IQ of actuarial science majors is assumed to be normally distributed with mean 112 and standard deviation of 14. In a class of 19 students, find the probability that the mean IQ of all 19 students is greater than 120.

Answer: 0.0064 - need work

Answer 1

Solution :

Given that ,

mean = = 112

standard deviation = = 14

n = 19

= 112

= / n = 14 / 19 = 3.2118

P( >120 ) = 1 - P( <120 )

= 1 - P[( - ) / < (120 -112) /3.2118 ]

= 1 - P(z <2.49 )

Using z table

= 1 - 0.9936

= 0.0064

probability= 0.0064