D Question 2
USF is interested in learning about
the average time it takes students to
drive to campus. USF randomly
sampled 238 students and asked
each to provide the amount of time
they spent traveling to campus. This
variable, travel time, was then used
to create a confidence interval and
to conduct a test of hypothesis, both
of which are shown in the printout
below.
One-Sample T Test
Null Hypothesis: mu = 20
Alternative Hyp: mu > 20
95% Conf Interval
Variable
n
r
F
SE
Upper
P
Mea
Lowe
1 pts
Travel Time 23.243
3133
0
T D
Cases Included 238
1.
20.655
25.83
2.47 237 0.0071
What assumptions are necessary for the/nof which are shown in the printout
below.
One-Sample T Test
Null Hypothesis: mu = 20
Alternative Hyp: mu > 20
95% Conf Interval
Variable
n
r
F
SE
Upper
P
Mea
Lowe
TravelTime
3133
20.655
0 2.47 237
Cases Included 238
T D
23.243
25.83
0.0071
1.
What assumptions are necessary for the
above test and confidence interval above
to be valid?
O The population variance must be
approximately normally distributed.
O The population of travel times must have
an approximate t-distribution.
The population of travel times must be
approximately normally distributed.
O None of these listed, since the Central
Limit Theorem can be applied when n ≥ 30
Fig: 1
Fig: 2
