Question

Starting salaries of 64 college graduates who have taken a statistics course have a mean of $42,500 with a standard deviation of $6,800. Find a 68% confidence interval for ?μ. (NOTE: Do not use commas or dollar signs in your answers. Round each bound to three decimal places.)

Answer 1

Solution :

sample size = n = 64

Degrees of freedom = df = n - 1 = 63

t _/2,df = 1.002

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

= 1.002 * (6800 / 64)

Margin of error = E = 851.7

The 68% confidence interval estimate of the population mean is,

- E < < + E

42500 - 851.7 < < 42500 + 851.7

41648.3 < < 43351.7

Confidence interval = 41648.300 to 43351.700