Question

If n=32, ¯xx¯(x-bar)=36, and s=5, construct a confidence interval at a 90% confidence level. Assume the data came from a normally distributed population.

Give your answers to one decimal place.

< μμ <

Answer 1

Solution :

Given that,

t _/2,df = 1.696

Margin of error = E = t_/2,df * (s /n)

= 1.696 * (5 / 32)

Margin of error = E = 1.5

The 90% confidence interval estimate of the population mean is,

- E < < + E

36 - 1.5 < < 36 + 1.5

34.5 < < 37.5