Question

In an experiment to determine the effect of ambient temperatures, on the emissions of oxides of nitrogen (NO₈) of diesel trucks, 10 randomly selected trucks were run at temperatures of 40° F and 80° F. The emissions, in parts per billion, are shown in the table below. It is desired to test the claim that the mean emissions are higher at 40° F, using a 1% level of significance.

Truck	1	2	3	4	5	6	7	8	9	10
40° F	834.7	753.2	855.7	901.2	785.4	862.9	882.7	740.3	748.0	848.6
80° F	815.2	765.2	842.6	797.1	764.3	819.5	783.6	694.5	772.9	794.7

1. This problem is about (circle the correct one):

One population proportion                      Two population proportions             

One population mean                             Two populations means (Independent samples)

One population standard deviation        Two populations means (paired samples)

Two population standard deviations

2. State the null and alternate hypotheses.

3. What is the level of significance?

Answer 1

a] Two populations means (paired samples)

b] H0:

Ha:

level of significance= 0.01

t= 2.713

degrees of freedom= 10-1=9

P value= 0.024/2= 0.012

Since P value > level of significance therefore NOT significant

Decision:DONOT REJECT H0.

CONCLUSION: WE DO NOT HAVE SUFFICIENT EVIDENCE TO CONCLUDE THAT the mean emissions are higher at 40° F.