# Question: When H0 is true this statistic has a t distribution

When H0 is true, this statistic has a t distribution based on (n + m – 4) df. The data below are a subset of the data in the article “Diet and Foraging Model of Bufa marinus and Leptodactylus ocellatus” (Journal of Herpetology [1984]: 138– 146). The independent variable x is body length (cm) and the dependent variable y is mouth width (cm), with n = 9 observations for one type of nocturnal frog and m = 8 observations for a second type. Carry out a test to determine if the slopes of the true regression lines for the two different frog populations are equal. Use a sigificance level of .05. (Summary statistics are also given in the accompanying table.)

Leptodactylus ocellatus

Bufa marinus

Leptodactylus ocellatus

Bufa marinus

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