A researcher surveys 25 people and finds that their average commute is 15 minutes with a standard deviation of 1.5 minutes. Calculate the 95 percent confidence interval on variance. Do most people have a commute of 20 minutes?
Confidence interval for variance? How is that different from normal variances? should I just use the variance instead of the standard deviation? so 1.5^2=2.25
root 25= 5
\(\displaystyle 15+1.96\frac{2.25}{5} \) and \(\displaystyle 15-1.96\frac{2.25}{5} \)
\(\displaystyle 15+0.882 \) and \(\displaystyle 15-0.882 \)
\(\displaystyle 15.88, 14.12 \)
so, no , most people will not have a commute of 20 minutes
Is this right?
Thanks!
Confidence interval for variance? How is that different from normal variances? should I just use the variance instead of the standard deviation? so 1.5^2=2.25
root 25= 5
\(\displaystyle 15+1.96\frac{2.25}{5} \) and \(\displaystyle 15-1.96\frac{2.25}{5} \)
\(\displaystyle 15+0.882 \) and \(\displaystyle 15-0.882 \)
\(\displaystyle 15.88, 14.12 \)
so, no , most people will not have a commute of 20 minutes
Is this right?
Thanks!