Question

If n=12, ¯x (x-bar)=34, and s=19, 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. < μ <

Answer 1

n=12

s=19

X=34

ConfLevel=90%

A confidence level of 90%

represent a Z statistical of 1.645

the Confidence interval is given by

$X\pm Z*\frac{s}{\sqrt{n}}$

then

$34\pm1.645*\frac{19}{\sqrt{12}}$$34\pm9.02254$

then the interval is

$25.0\leq u\leq43.0$