Hasan O.

# why the average of the two 95% confidence interval limits for lower and upper speeds not equal to average speed based on average running time ?

for example : Given the normal distribution of running times, the
mean running time for the section (3mi) is 196 seconds, and 95% of
all running times would fall within 1.96(15) = 29.4 seconds of
this value. Thus the 95% interval for travel times would be
between 196 - 29.4 = 166.6 seconds and 196 + 29.4 = 225.4
seconds. The speeds corresponding to these running times
(including the average) are:
S 1 = (3mi/225.4s)*(3600s/h) = 47.9 mi/hr
S av =(3mi/196s)*(3600s/h) = 55.1 mi/hr
S 2 = (3mi/166.6s)*(3600s/h) = 64.8 mi/hr

S1 + S2 not equal to =55.1 why?

By: Tutor
5 (53)

College Professor & Expert Tutor In Statistics and Calculus

## Still looking for help? Get the right answer, fast.

Get a free answer to a quick problem.
Most questions answered within 4 hours.

#### OR

Choose an expert and meet online. No packages or subscriptions, pay only for the time you need.