Question

A soccer ball manufacturer wants to estimate the mean circumference of soccer balls within 0.1 inch.

Answer 1

Answer:

Step-by-step explanation:

Given that a soccer ball manufacturer wants to estimate the mean circumference of soccer balls within 0.1 inch.

a) sigma = 0.25

Since population std dev is known we can use Z critical value i.e. 2.58

$2.58(\sigma/\sqrt{n} )25.8*\sigma\\i.e. n>665.64 \sigma^2$

Hence when sigma =0.25

we get n should be atleast = 41.6025 or 42

b) when sigma = 0.3 we get

n >59.390=60

c) Big std deviation requires larger sample size.