1)A manufacturer of automobile shock absorbers was interested in comparing the durability of its shocks with that of the shocks produced by its 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 4 cars.After the cars had been driven 30,000 miles, the strength of each test shock was measured, coded and recorded.Results of the examination are shown below.

Car number

Manufacturer's Shock

Competitor's Shock

1

10.0

9.5

2

9.5

9.0

3

11.0

10.0

4

7.5

8.0

Do the data present sufficient evidence to conclude that there is a difference in the mean strength of the two types of shocks after 30,000 miles of use? Use alpha = .05.