Page 236 - Six Sigma Demystified

216 Six SigMa DemystifieD

TAble T.3 Expected Preferences for Each Show assuming
independence

Sex Show 1 Show 2 Show 3 Total
Male 136 136 68 340
Female 64 64 32 160
Totals 200 200 100 500

Contingency Table

Minitab

Menu: Stat\Tables\Chi-Square Test (two-way table)

Example
Expected counts are printed below observed counts, and chi-square contribu-
tions are printed below expected counts.

Show 1 Show 2 Show 3 Total
1 160 140 40 340
136.00 136.00 68.00
4.235 0.118 11.529
2 40 60 60 160
64.00 64.00 32.00

9.000 0.250 24.500
Totals 200 200 100 500
Chi-square = 49.632; df = 2; p value = 0.000.
Excel

CHITEST(a , e ) reports p.
ii
ii
Example
For actual data (excluding labels) in cells B2:D3 and expected data in cells B7:D8,
CHITEST(B2:D3, B7:D8) returns a value p = 0.00. Since p < 0.05, reject the null
that the percentages of males and females preferring each show are equal.