Question

A particular fish population has a mean length of 230 mm and a standard deviation of 50 mm. What is the probability that a random sample of 16 fish from this population has a mean length of at least 240 mm?

Answer 1

Solution :

Given that,

mean = =230

standard deviation = =50

n = 16

= 230

= / n = 50 16 = 12.5

P ( 240)

= 1 - P (   240 )

= 1 - P ( - /)   (240 - 230 /0.8)

= 1 - P( z   10 / 12.5 )

= 1 - P ( z 0.8 )   

Using z table

= 1 - 0.7881

= 0.2119

Probability = 0.2119