Question

The mean weight of an adult is 62 kilograms with a variance of 144. If 195 adults are randomly selected, what is the probability that the sample mean would be less than 59.5 kilograms? Round your answer to four decimal places.

Answer 1

Solution :

Given that ,

mean = = 62

standard deviation = = 144=12

n = 195

= 62

=  / n = 12/ 195=0.8593

P( <59.5 ) = P[( - ) / < (59.5 -62) / 0.8593]

= P(z < -2.91)

Using z table  

= 0.0018

probability=0.0018