A behavioral neuroscientist studies the role of the neurotransmitter serotonin on aggressive behavior. One group of rats serves as a control and receives a placebo. A second group receives a drug that raises levels of serotonin in the brain. The researchers then measure the animals for aggressive behavior toward other rats and ask "Do the different treatments have an effect on aggressive behavior?" Using the data below... Placebo +Serotonin A) State the null and alternative hypotheses B) Calculate the appropriate test statistic 19 C) Describe the null distribution and find the critical value (assuming a=0.05) 5 11 D) State your conclusion about the null hypothesis 12 18 E) Quantify the effect size in this study 10 10 Note: Assume that variances are unequal, but that all other test assumptions are satisfied (e.g. 10 12 use Welch's t-test). The researcher has already done some of the calculations and found that SSplacebo=50 and SSserotonin=70. 7 14