Question 16 A manufacturer of automobile shock absorbers was interested in comparing the durability of
its shocks with that of the biggest competitor. To make the comparison, one of the
manufacturer's and one of the competitor's shocks were randomly selected and installed on
the rear wheels of six cars. After the cars had been driven 20,000 km, the strength of each
shock was measured, coded and recorded. The following are the results of the examination:
Car No.
1
2
3
4
5
6
Manufacture's
8.8
10.5
12.5
9.7
9.6
13.2
Competitor's
8.4
10.0
12.0
9.3
9.0
13.0
Do the data present sufficient evidence to conclude that there is a difference in the mean
strength for the two types of shocks after 20,000 km of use? Test using level of significance,
a = 0.05.