Many smartphones, especially those of the LTE-enabled persuasion, have earned a bad rap for exceptionally bad battery life. Battery life between charges for the Motorola Droid Razr Max averages 20 hours when the primary use is talk time and 7 hours when the primary use is Internet applications (The Wall Street Journal, March 7, 2012). Since the mean hours for talk time usage is greater than the mean hours for Internet usage, the question was raised as to whether the variance in hours of usage is also greater when the primary use is talk time. Sample data showing battery hours of use for the two applications follows. Talk Time Internet
35.8 14
22.2 12.5
4 16.4
32.6 1.9
8.5 99.9
42.5 5.4
8 1
3.8 15.2
30 4
12.8 4.8
10.3 35.5
Formulate hypotheses about the two population variances that can be used to determine if the population variance in battery hours of use is greater for the talk time application.
b. What are the standard deviations of battery hours of use for the two samples? Round your answers to two decimal places.
s1 =
s2 =
c. Conduct the hypothesis test and compute the p-value. Round your answers to three decimal places.
The value of F is:
p-value is: