A customer service representative was interested in comparing the average time (in minutes) customers are placed on hold when calling Southern California Edison and Southern California Gas companies. The representative obtained two independent random samples and calculated the following summary information: So Cal Edison
So Cal Edison So Cal Gas
Sample Size 9 12
Sample Mean 3.2 min 2.8 min
Sample Std Dv .5 min .7 min
Assume the distributions of time is on hold are approximately normal. Using the following null and alternative hypothesis
Ho:m1-m2 vs. Ha: mu1-mu2 not equal 0
Test Statistic is t=-1.455
Assume alpha is .1 what is the appropriate conclusion for this test?
a- reject Ho
b- do not reject Ho
c- reject Ha
d- none of these