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Jon wants to know if people who live alone have more pets than people who live w

ID: 3225277 • Letter: J

Question

Jon wants to know if people who live alone have more pets than people who live with others. To test this hypothesis, Jon collects data from a random sample of n = 122 Americans. He finds that 61 people in his sample live alone and have a mean number of pets of M = 1.5 with a standard deviation of s = 0.5. He finds that n = 61 people in his sample live with others and have a mean number of pets of M = 1 with a standard deviation of s = 1. Jon wants to conduct an independent samples t-test to see if results suggest that people who live alone have significantly (alpha = .01) more pets than people who live with others. Jon computes a t-observed (Step 3) for his sample of 2.890. What is the effect size (r^2) for this t-test? Explain what it tells you about the differences/variance in number of pets.

Explanation / Answer

Effect size r2=t2/(t2+df)=2.8902/(2.8902+(122+61-2)) = 0.0441

As effect size is between 0.01 to 0.09, so is is small to medium.

This means that living alone explains 4.41% of variance in having pets.