Duration/hours |
---|
0.7 |
1.0 |
1.5 |
1.6 |
1.7 |
1.8 |
1.8 |
1.9 |
2.0 |
3.0 |
1. This afternoon, 04 November 2005 at 4:00 P.M., the college will hold a 10.329 km fun walk/run from the campus to Spanish Wall. The college has not done this walk in many years, not since the late 1990s. The duration in hours of ten randomly selected students was recorded during the last walk. Use the data to determine the sample mean x and the sample standard deviation sx. Use the n, x, and sx to calculate a 95% confidence interval c for the population mean walk duration.
Confidence interval statistics | |||
---|---|---|---|
Degrees of freedom | df | = n-1 | =COUNT(data)-1 |
Find a t_{c} value from a confidence level c and sample size n | t_{c} | =TINV(1-c,n-1) | |
Calculate an error tolerance E of a mean for any n ≥ 5 using sx. | E | =t_{c}*sx/SQRT(n) | |
Calculate a confidence interval for a population mean µ from a sample mean x and an error tolerance E | x-E≤ µ ≤ x+E |
For those who like to work with a sketch: