# Statistics - Confidence Interval.

The following random sample from a population whose values were normally distributed was collected.

10 8 11 11

The 95% confidence interval for m is

a) 8.52 to 10.98

b) 7.75 to 11.75

c) 9.75 to 10.75

d) 8.00 to 10.00

#### Solution Preview

... =sqrt[ sum(d^2) /(n - 1)] = sqrt(6/3) = sqrt 2

SE = SD/sqrt n = sqrt 2 / sqrt 4 = 0.7071

Degrees of freedom ...