Question

A simple random sample of size n = 64 is obtained from a population with µ = 112 and σ = 24.
What is P(x ¯ ≤ 109.5)?

(Give answer in decimal form and round answer to two decimal places)

Answer 1

Solution :

Given that,

mean = = 112

standard deviation = = 24

n = 64

= 112

= / n = 24 64 = 3

p (   109.5 )

P ( - /)   (109.5 - 112 / 3)

P( z -2.5 / 3 )

P ( z -0.83 )   

Using z table

= 0.2033

Probability = 0.20