Question

Truck pollution: In an experiment to determine the effect of ambient temperature on the emissions of oxides of nitrogen (NOx) of diesel trucks, 10 trucks were run at temperatures of 40°F and 80°F. The emissions, in parts per billion, are presented in the following table.

Truck                         40° F                              80° F

1                                 834.7                             815.2

2                               753.2                               755.2

3                                855.7                             812.6

4                              901.2                               797.1

5                                785.4                              744.3

6                                862.9                              819.5

7                                882.7                              783.6

8                               740.3                               694.5

9                              748.0                                 732.9

10                           848.6                                  794.7

a. Construct a 95% confidence interval for the difference between the parameters of interest. Show all work including formula used. b. Interpret the interval. c. Researchers claim that the population mean emission of oxides of nitrogen from diesel trucks run at 80 degrees F is more than 20 points lower than that of trucks run at 40 degrees F. Do you agree with the claim? Explain

Answer 1

( 40° F ) sample 1 :

mean = 821.27

SD :

( 80° F ) sample 2 :

mean = 774.96

SD :

TEST :

a.

b.

we can say with 95% confidence that the value in 40° F - value in 80° F is in the range (1.33, 91.29)

c.

we will reject the claim as the confidence interval contains values less than 20 too

(please UPVOTE)