w,try the example again, buteach subgroupis now going to be from a different population (so, the
del”,which anova assumes, will be wrong):

SubgroupA: X-bar = 40, sigma = 10
SubgroupB: X-bar = 50, sigma = 10
SubgroupC: X-bar = 55, sigma = 10

B >Erase C1 -C20
B >Random25C1;
BC>Normal4010.
B >Random25C2;
BC>Normal5010.
B >Random25C3;
BC>Normal5510.
B >Desc C1 -C3

N
25
25
25

Mean
42.38
53.48
56.31

Median
41.29
53.41
55.05

TRMean
42.72
53.68
55.87

StDev
9.26
11.46
13.32

SeMean
1.85
2.29
2.66

Min
18.40
29.00
30.91

Max
58.77
73.31
91.67

Q1
38.10
46.04
46.73

Q3
50.02
61.79
63.05

B >

AovonewayC1 -C3

lysis ofvariance
rceDFSS
tor22707
or729464
al7412172

MS
1354
131

F
10.30

Individual 95 pctCi’s for mean based on pooledStdev

el

N
25
25
25

Mean
42.38
53.48
56.31

Stdev
9.26
11.46
13.32

—————+————+————+———
(———*——)
(——*——)
(——*——)
—————+————+————+———
45.052.560.0

led Stdev = 11.47

cial Case:

TwoSubgroups

Parent

Population "w"

2

=SWithin

2

=

S
1

2

+S22
2

Parent

Population "B"

2

=SBetween

2

=N Sx

2

Reminder:S2

=

Σ(X -X

)2
N - 1

∴SX

2

=

Σ(X

-X)2
No. of subgroups -1