Question

A researcher conducts an independent-measures study to examine how the brain chemical serotonin is related to aggression. One sample of rats serves as a control group and receives a placebo that does not affect normal levels of serotonin. A second sample of rats, low serotonin group, receives a drug that lowers brain levels of serotonin. Then, the researcher tests the animals by recording the number of aggressive responses each of the rats display. See the data below. Is there a significant difference between the control group and the low serotonin group regarding the number of aggressive responses?

                                               Control         Low Serotonin  

                                                 n = 10                 n = 15

                                               M = 14               M = 19

                                               SS = 180.5       SS = 130

Perform a hypothesis test using independent-measures t-test. Use a two-tailed test with α = .05, and answer the following questions.

You will be using a independent-measures t-test because ___________________

Select all the correct answers

Group of answer choices

You do not know the population mean and population standard deviation

You are using data from a single sample

You know the population standard deviation, but not the population mean

you can use either independent-measures or repeated-measures t test

You know the population mean, but not the population standard deviation

You are comparing the means of two different samples

Answer 1