1. A group of Internet users 50-65 years of age were randomly chosen and asked to report the weekly number of hours they spend online. The purpose of the study was to determine whether the mean weekly number of hours that Internet users in that age group spend online differs from the mean for Internet users in general, which is 12.5 (as reported by "The Digital Future Report: Surveying the Digital Future, Year Four"). The following information is available:
Test of mu = 12.5 vs mu not = 12.5
Variable N Mean St. Dev SE Mean
hr. online 125 12.008 3.214 0.287
Variable 95.0% CI T P
hr. online (11. 439, ) -1.71 0.090
The population standard deviation is apparently:.
a. unknown
b. 3.214
c. 0.287
2. Note that the upper limit of the 95% confidence interval has been edited out. Which of the following is the number that has been edited out?
a. 12.375
b. 12.577
c. 13.439
3. If we suspected that the mean were less than 12.5, and carried out a one-sided test at the .05 significance level, we would conclude that the mean weekly number of hours that Internet users 50-65 years of age spend online:.
a. equals 12.5.
b. may equal 12.5.
c. is apparently different from 12.5.
d. is apparently less than 12.5.