Example
A company manufactures large rocket engines used to project
satellites into space. The government buys the rockets, and the
contract specifies that these engines are to use an average of 5550 lb
of rocket fuel the first 15 sec operation. The company claims their
engines fit specifications. To test the claim an inspector randomly
selects six such engines from the warehouse. These 6 engines are
fired 15 sec each and the fuel consumption for each engine is meas-
ured. For all six engines, the mean fuel consumption is
ooooo
= 5750
pounds and the standard deviation is
x
"
n
-1
= 250 lb. Is the claim
justified at the 5% level of significance?
Procedure
1
m
STAT2
2
3
(TEST)
c
(T)
b
(1-Smpl)
3
2
(VAR)
c
1
(
!
)
c
fffa
w
fhfa
w
cfa
w
g
w
1
(None)
c
4
1
(CALC)
6
(DRAW)
Result Screen
11
examples
Since P = 0.107344401 > 0.05 (level of significance), we can’t reject the null hypothesis
µ
=5550 and conclude that the data does not present sufficient evidence to indicate that the
average fuel consumption from the first 15 seconds of operation is different from
µ
=5550.
