A study of the ability of individuals to walk in a straight line reported that accompanying data on cadence (strides per seconds) for a sample of n =
20 randomly selected healthy men:
.95 .81 .93 .95 .93 .86 1.05 .92 .85 .81
.92 .96 .92 1.00 .78 1.06 1.06 .96 .85 .92
A normal probability plot gives substantial support to the assumption that
the population distribution of cadence is approximately normal. A descriptive
summary of the data from MINITAB follows.
Variable N Mean Median StDev SEMean
Cadence 20 0.9255 0.9300 0.0809 0.0181
a. Calculate and interpret a 95% confidence interval for a population mean
cadence.
b. Calculate and interpret a 95% prediction interval for the cadence of a
single individual randomly selected from this population.
c. Calculate an interval that includes at least 99% of the cadences in the
population distribution using a confidence level of 95%.