I am trying to learn to rollerblade The following data are t
I am trying to learn to roller-blade. The following data are times (in seconds) between crashing to the ground: 64, 47, 15, 39, 92, 62, 77, 28, 30, 386, 55, 28, 104, 126. Find a 95% confidence interval for the mean time between crashes assuming the data follows an exponential distribution.
Solution
Confidence Interval
 CI = x ± t a/2 * (sd/ Sqrt(n))
 Where,
 x = Mean
 sd = Standard Deviation
 a = 1 - (Confidence Level/100)
 ta/2 = t-table value
 CI = Confidence Interval
 Mean(x)=82.357
 Standard deviation( sd )=93.03
 Sample Size(n)=14
 Confidence Interval = [ 82.357 ± t a/2 ( 93.03/ Sqrt ( 14) ) ]
 = [ 82.357 - 2.1604 * (24.86331) , 82.357 + 2.1604 * (24.86331) ]
 = [ 28.6423,136.0717 ]

