Question

A new chemotherapy drug is released to treat leukemia and researchers suspect that the drug may have fewer side effects than the most commonly used drug to treat leukemia. The two drugs have equivalent efficacy. In order to determine if a larger study should be conducted to look into the prevalence of side effects for the two drugs, set up a Mann-Whitney U test at the alpha equals .05 level and interpret its results.

                        Number of Reported Side-Effects

Old Drug           0          1          3          3          5

New Drug         0          0          1          2          4

Old Drug	New Drug	Total Sample (Ordered Smallest to Largest)		Ranks
		Old Drug	New Drug	Old Drug	New Drug
				R1=	R2=

A) We fail to reject H₀, which states the two populations are equal at the alpha equals .05 level because the calculated U value of 16.5 is greater than the critical U value of 2.

B) We fail to reject H₀, which states the two populations are equal at the alpha equals .05 level because the calculated U value of 8.5 is greater than the critical U value of 2.

C) We reject H₀ in favor of H₁, which states the two populations are not equal at the alpha equals .05 level because the calculated U value of 16.5 is greater than the critical U value of 2.

D) We reject H₀ in favor of H₁, which states the two populations are not equal at the alpha equals .05 level because the calculated U value of 8.5 is greater than the critical U value of 2.

Answer 1

Old Drug	New Drug	Total Sample		Ranks
		(Ordered Smallest to Largest)
		Old Drug	New Drug	Old Drug	New Drug
0	0	0	0	2	2
1	0	1	0	4.5	2
3	1	3	1	7.5	4.5
3	2	3	2	7.5	6
5	4	5	4	10	9
				R1=31.5	R2=23.5

U1=n1n2+n1(n1+1)/2-ΣR1

=

8.5

B) We fail to reject H₀, which states the two populations are equal at the alpha equals .05 level because the calculated U value of 8.5 is greater than the critical U value of 2.