Analyis of Rogaine

select worksheet Rogaine.mtw with data in the form of a table

Step 1: Graph
'No Growth' 'New Vellus' 'Min Growth' 'Mod Growth' 'Den Growth' Graph > Bar Chart > Values from a table, Two-way table, Cluster > Graph Variables: 'No Growth' 'New Vellus' 'Min Growth' 'Mod Growth' 'Den Growth', Row labels: Groups, check Rows are outermost..., Bar Chart Options > Check show y as percent, Within categories at level 1.

Step 2: Contingency table

No Growth New Vellus Min Growth Mod Growth Dense Growth Total

Treatment 301 172 178 58 5 714

Control 423 150 114 29 1 717

Total 724 322 292 87 6 1431

	No Growth	New Vellus	Min Growth	Mod Growth	Dense Growth	Total
Treatment	301	172	178	58	5	714
Control	423	150	114	29	1	717
Total	724	322	292	87	6	1431

Step 3: Test

Stat > Tables > Chisquare test > Columns containing the table: 'No Growth' 'New Vellus' 'Min Growth' 'Mod Growth' 'Den Growth'
this gives a warning of some expected cell counts less than five. Those are for "Dense Growth'. Join categories 'Mod Growth' and 'Dense Growth', call new category 'Some Growth'
Stat > Tables > Chisquare test > Columns containing the table: 'No Growth' 'New Vellus' 'Min Growth' 'Some Growth'
1) α=0.05
2) H₀: Classifications are independent (no relationship between the Group and Growth, Rogaine does not work)
3) H_a: Classifications are dependent (some relationship between the Group and Growth, Rogaine works)
4) p=0.000 < α
5) Reject H₀, Rogaine works