Question

Samples of three different species of amphibian (frog, toad and salamander) were collected and dissected and the number of parasites found within each was counted and recorded. The researchers are interested in determining whether the distribution of parasites across species is different. The number of parasites within each sample was counted and recorded.

Frogs	Toads	Salamanders
7	7	3
5	6	3
6	11	2
5	8	5
7	2	4
5	10	2
5	6	5
5	2	2
5	8
6
8

H₀: μ₁ = μ₂ = μ₃

H_a: μ_i ≠ μ_j for some i ≠ j

What is the average rank for the toad group?

What is the average rank for the frog group?

What is the average rank for the salamander group?

Calculate the test statistic

Which interval in the table contains the p value for the test?

p-value ≤ 0.005
0.005 < p-value ≤ 0.01
0.01 < p-value ≤ 0.025
0.025 < p-value ≤ 0.05
0.05 < p-value ≤ 0.1
p-value > 0.1

Answer 1

What is the average rank for the toad group?

18.89

What is the average rank for the frog group?

16.45

What is the average rank for the salamander group?

6.88

Calculate the test statistic

10.057

Which interval in the table contains the p value for the test?

0.005 < p-value ≤ 0.01

	Median	n	Avg. Rank
	5.00	11	16.45	Frogs
	7.00	9	18.89	Toads
	3.00	8	6.88	Salamanders
	5.00	28		Total
			10.057	H
			2	d.f.
			.0065	p-value