User Manual

37
examples
Example Factory A and Factory B both manufacture the same item. To compare
the productivity of the two factories, the production data shown below
was collected for 10 items at Factory A and nine items at Factory B.
Factory A: 78, 80, 79, 83, 82, 85, 78, 74, 76, 84 (kg/h)
Factory B: 81, 84, 82, 88, 86, 83, 78, 84, 89 (kg/h)
Construct a 95% confidence interval for the difference between µ 1 and
µ 2 when the following is assumed: σ 1
2
= σ 2
2
, Factory A population
distribution is N( µ 1, σ 1
2
), and Factory B population distribution is N( µ 2,
σ 2
2
).
Procedure
1 m STAT2
2hiwiawhjwidwicw
ifwhiwhewhgwiew
e
ibwiewicwiiwigw
idwhiwiewijw
3 4(INTR) c(T)c(2-Smpl)
4 1(LIST) c
.jfw
1(LIST)bwc
1(LIST)cwc
1(1)c
1(1)c
1(On)c
1(None)c
5 1(CALC)
Result Screen
Thus, the 95% confidence interval for µ 1- µ 2 becomes -7.4< µ 1- µ 2<-0.6.