Frozen computer: A computer system administrator noticed that computers running a particular operating system seem to freeze up more often as the installation of the operating system ages. She measures the time (in minutes) before freeze-up for

6

computers one month after installation and for

6

computers seven months after installation. The results are shown. Can you conclude that the time to freeze-up differs in variability in the seventh month and the first month after installation? Let

1

denote the variability in time to freeze-up in the first month after installation. Use the

=0.05

level and the critical value method with the table.

One month:	215.9	235.1	225.6	244.4	245.3	207.4
Seven months:	127.3	201.3	174.2	246.2	149.4	84.3

(a)Find the critical value. Round the answer to two decimal places.

The critical value

f0.025

is

(b)Compute the test statistic. Round the answer to two decimal places.