Download To Do Now After 6

To Do Now After 6.1
To Do Now After 6.1
1. Julia enjoys jogging. She has been
jogging over a period of several years,
during which time her physical condition
remained constantly good. Usually, she
jogs 2 miles per day. During the past
year Julia has sometimes recorded her
time to run 2 miles. She has a sample
of 90 of these times. For these 90
times, the mean was 15.60 minutes and
the standard deviation was 1.80
minutes. Let  be the mean jogging
time for the entire distribution of her
running times taken over the past year.
Find a 95% confidence interval for  .
1. Julia enjoys jogging. She has been
jogging over a period of several years,
during which time her physical condition
remained constantly good. Usually, she
jogs 2 miles per day. During the past
year Julia has sometimes recorded her
time to run 2 miles. She has a sample
of 90 of these times. For these 90
times, the mean was 15.60 minutes and
the standard deviation was 1.80
minutes. Let  be the mean jogging
time for the entire distribution of her
running times taken over the past year.
Find a 95% confidence interval for  .
2. Walter usually meets Julia at the track.
He prefers to jog 3 miles. While Julia
kept her record, he also kept his own.
For his 90 times, the mean was 22.50
minutes and the standard deviation was
2.40 minutes. Let  be the mean
jogging time for the entire distribution of
his running times over the past several
years. Find a 99% confidence interval
for  .
2. Walter usually meets Julia at the track.
He prefers to jog 3 miles. While Julia
kept her record, he also kept his own.
For his 90 times, the mean was 22.50
minutes and the standard deviation was
2.40 minutes. Let  be the mean
jogging time for the entire distribution of
his running times over the past several
years. Find a 99% confidence interval
for  .