Question

Salaries of 45 college graduates who took a statistics course in college have a mean, x, of $ 64,900 . Assuming a standard deviation, q, of $19,881 , construct a 95 % confidence interval for estimating the population mean u.

$ -----<μ< $------ round to nearest integer as needed

Answer 1

Solution :

sample size = n = 45

Degrees of freedom = df = n - 1 = 44

t _/2,df = 2.015

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

= 2.015 * (19881 / 45)

Margin of error = E = 5971.8

The 95% confidence interval estimate of the population mean is,

- E < < + E

64900 - 5971.8 < < 64900 + 5971.8

$58928 < < $70872