=+if the slopes of the true regression lines for the two different frog populations are equal. (Summary statistics are given in the table.)

Leptodactylus ocellatus x 3.8 4.0 4.9 7.1 8.1 8.5 8.9 9.1 9.8 y 1.0 1.2 1.7 2.0 2.7 2.5 2.4 2.9 3.2 Bufa marinus x 3.8 4.3 6.2 6.3 7.8 8.5 9.0 10.0 y 1.6 1.7 2.3 2.5 3.2 3.0 3.5 3.8 Leptodactylus Bufa Sample size: 9 8 64.2 55.9 500.78 425.15 19.6 21.6 47.28 62.92 153.36 163.36