You are working on a project to determine whether community crime prevention efforts are effective at reducing crime level. You collected data on the number of crimes for a sample of 9 gated communities that implemented the crime prevention efforts (experimental group) and 9 gated communities that did not receive the crime prevention efforts (control group). Your hypothesis is that the experimental group has a lower mean number of crimes than the control group (i.e., community crime prevention measures are effective).

What is the null hypothesis in this study?

Group of answer choices

There is no difference between the experimental and control groups.

Experimental group has a lower mean number of crimes than the control group.

Experimental group has a higher mean number of crimes than the control group.

There is a difference between the experimental and control groups.