In: Statistics and Probability
A bank with branches located in a commercial district of a city and in a residential district has the business objective of developing an improved process for serving customers during the noon-to-1 P.M. lunch period. Management decides to first study the waiting time in the current process. The waiting time is defined as the time that elapses from when the customer enters the line until he or she reaches the teller window. Data are collected from a random sample of 15 customers at each branch.
The following is the data sample of the wait times, in minutes, from the commercial district branch.
4.12 5.39 3.21 5.06 4.57 2.39 3.52 3.36
4.64 6.15 0.07 5.03 6.62 6.46 3.64
The following is the data sample of the wait times, in minutes, from the residential district branch.
9.95 5.76 8.09 5.73 8.86 3.97 8.08 8.46
10.66 6.94 5.44 4.01 6.14 9.92 5.58
Assuming that the population variances from both banks are not equal, is there evidence of a difference in the mean waiting time between the two branches? (Use
Determine the hypotheses. which is Ho: m1 =m2, H1: m1 is not = to m2
the test statistic is -4.0836
What are the critical values?
choose the correct conclusion below?
a-reject ho there is insufficient evidence
b-do not reject ho there is insufficient evidence
c-do not reject ho there is sufficient evidence
d-reject ho there is sufficient evidence
part b
determine the p value and interpret its meaning
part c
in addition to unequal variances what asssumption is necessary in a?
a- since the sample sizes are both less than 30, it must be assumed that the samples are specifically chosen and not independantly sampled.
b-since the sample sizes are both less than 30, it must be assumed that the sample variances are equal
c- since the sample sizes are both less than 30, it must be assumed that both populations are approximately normal
d- since the sample sizes are both less than 30, it must be assumed that the sample sizes are equal
part d
construct a 90 % interval estimate of the difference between the populations means in the two branches
the confidence interval is blank is less than or equal to m1 - m2 which is less than or equal to blank