Question

Hermit crabs fight for ownership of shells. Fights are initiated when one crab raps on the shell of another with its big claw. An exchange of shells occurs approximately 50% of the time. Investigators wish to see if the rapping force helps decide the issue. They set up an experiment with a rubberized shell, which would dampen the force of the rapping. They reason that the reduced force should result in fewer exchanges of shells. What null and alternative hypotheses should the investigators use? H subscript 0 : space p equals 0.50 comma space H subscript a : space p greater than 0.50 H subscript 0 : space p equals 0.50 comma space H subscript a : space p less than 0.50 H subscript 0 : space p equals 0.50 comma space H subscript a : space p not equal to 0.50 H subscript 0 : space p equals 0.50 comma space H subscript a : space p less or equal than 0.50

Answer 1

Solution :

This is the left tailed test .

The null and alternative hypothesis is

H₀ : p = 0.50

H_a : p < 0.50