Bobby does not want to be late to work again He drives to wo

Bobby does not want to be late to work again. He drives to work every morning from Oakland to San Francisco and crossing the Bay Bridge seems to take forever. He times himself crossing the bridge for seven consecutive mornings, with the resulting times of 22.34, 27.54, 15.26, 13.56, 18.57, 21.22, and 19.08 minutes. Construct a 99% confidence interval from those times.How would i solve this in excel?

Solution

use CONFIDENCE.T(0.01,4.6512,7) function in excel, we get 6.5176. Now subtract the mean of the sample 19.6528 from this value and add the mean with this value. 4.6512 is the standard deviation of the sample.

CI is (13.1351,26.1705)