Two groups of subjects participated in an experiment designed to test the effect of frustration on aggression. The experimental group of 40 subjects received a frustrating puzzle to solve, while the...

Two groups of subjects participated in an experiment designed to test the effect of frustration on aggression.  The experimental group of 40 subjects received a frustrating puzzle to solve, while the control group of 70 subjects received a very easy version of the same puzzle.  Levels of aggression was measured for both groups where higher scores are indicative of higher levels of aggression.  The experimental group (high frustration) had a mean aggression score of 4.0 and a standard deviation of 2.0.  The control group (no frustration) had a mean aggression score of 3.0 and a standard deviation of 1.5.  Please identify: (1) the research and null hypothesis, (2) the critical value needed to reject the null, (3) the decision that you made upon analyzing the data, and (4) the conclusion you have drawn based on the decision you have made.

formulate a research and null hypothesis and test the null hypothesis at the .01 level of significance.