Question

If n=28, ¯ x (x-bar)=50, and s=5, construct a confidence interval at a 99% confidence level. Assume the data came from a normally distributed population. Give your answers to one decimal place.

Answer 1

Explanation:

Given that

n=28, ¯ x (x-bar)=50, and s=5

Here only sample std deviation is known, hence we can use only t critical value

df =n-1 =27

t critical = 2.05

Margin of error =
`2.05 *(s)/(√(n) ) \\=1.937`

Confidence interval = 28±1.937

=(26.1, 29,9)