Question 315:

Asked on August 5, 2008

Tags: Confidence Intervals , Standard Deviation , t-statistic , Critical Value , Standard Error of the Mean

1

Answer:

No answer provided yet.

1. The mean is 32.08
2. Standard deviation is .6730
3. The Standard Error of the Mean (SEM) is sd/SQRT(n) = .6730/3.162 = .2128
4. The critical value from the t-distribution for a 95% CI can be found using Excel =TINV(0.05,9) = 2.262
5. The margin of error is the critical value * them SEM = 2.262*.2128 =.4813
6. The 95% CI is the mean minus and plus the margin of error = 32.08 +/- .4813
7. The 95% Confidence Interval is then (31.95, 32.56)