The data listed below contain brain weights (in ounces) for three species of adu

Question

The data listed below contain brain weights (in ounces) for three species of adult primates who all have similar body masses. The research question was to determine if the means were the same or different between the 3 species. What test would be used to determine this, and justify why it would be used with assumptions.

brain_weight species 37.78 Species B 39.16 Species B 47.12 Species A 42.01 Species B 35.68 Species C 36.03 Species C 46.81 Species A 38.01 Species B 41.9 Species B 46.44 Species A 41.93 Species B 48.15 Species A 46.34 Species A 42.18 Species B 38.07 Species B 36.52 Species C 50.26 Species A 46.75 Species A 37.4 Species B 39.78 Species B 35.17 Species C 38.87 Species B 35.45 Species C 36.03 Species C 37.1 Species C 37.97 Species B 37.87 Species B 36.78 Species C 38.23 Species B 46.64 Species A 37.02 Species C 47.12 Species A 47.43 Species A 36.66 Species C 40.66 Species B 39.63 Species B 34.57 Species C 46.94 Species A 48.36 Species A 48.07 Species A 50.12 Species A 38.2 Species B 46.67 Species A 38.1 Species B 43.09 Species B 36.11 Species C 40.57 Species B 41.69 Species B 41.47 Species B 38.79 Species B 38.13 Species C 34.63 Species C 36.82 Species C 48.34 Species A

Explanation / Answer

Here we need to compare more than two means so one way ANOVA will be used.

Hypotheses are:

H0: The means were the same between the 3 species.

Ha: The means were the different between the 3 species.

Following is the output of one way analysis:

The test statistics is

F = 259.12

The p-value is 0.0000

Since p-value is less than 0.05 so we reject the null hypothesis.

That is we cannot conclude that men is same for all the three species.

Assumptions:

The brain weights of underlying populations are normally distributed and population variances are equal.

One factor ANOVA Mean n Std. Dev 47.598 16 1.2129 Species A 39.711 23 1.7988 Species B 36.180 15 0.9753 Species C 41.067 54 4.7373 Total ANOVA table Source SS    df MS F    p-value Treatment 1,082.8724 2 541.43618 259.12 1.92E-27 Error 106.5658 51 2.08952 Total 1,189.4381 53

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.