Two different chemical formulations of rocket fuel are considered for the peak thrust

Chapter 6, Problem 19

(choose chapter or problem)

Two different chemical formulations of rocket fuel are considered for the peak thrust they deliver in a particular design for a rocket engine. The thrust/weight ratios (in kilograms force per gram) for each of the two fuels are measured several times. The results are as follows:

Fuel A:         54.3         52.9         57.9         58.2         53.4         51.4

56.8         55.9         57.9         56.8         58.4         52.9

55.5         51.3         51.8         53.3

Fuel B:         55.1         55.5         53.1         50.5         49.7         50.1

52.4         54.4         54.1         55.6         56.1         54.8

48.4         48.3         55.5         54.7

a. Assume the fuel processing plant is presently configured to produce fuel B and changeover costs are high. Since an increased thrust/weight ratio for rocket fuel is beneficial, how should the null and alternate hypotheses be stated for a test on which to base a decision whether to switch to fuel A?

b. Can you conclude at the 5% level that the switch to fuel A should be made?