To investigate the effect of four treatments on change in body fat mass each of 74 male subjects who were over age 65 was assigned at random to one of the following four treatments: (1) placebo "growth hormone" and placebo "steroid" (denoted by P+ P), (2) placebo "growth hormone" and the steroid testosterone (denoted by P+ S), (3) growth hormone and placebo "steroid" (denoted by G+ P), and (4) growth hormone and the steroid testosterone (denoted by G+ s). The accompanying table lists data on change in body fat mass over the 26-week period following the treatment. Carry out an F test to see whether true mean change in body fat mass differs for the four treatments if N = 74, grand total T = -158.0, and = T/N= -2.135. (Round all your intermediate calculations to three decimal places.) Change in Body Fat Mass (kg) Treatment P+ PP+s G+PG+S 0.7 -4.9 1.6 -6.3 0.7 -0.8 -2.8 -4.8 -0.1 -1.5 A 126 -0.1 -1.5 -1.8 -2.6 -5.1 -5.7 1.1 -0.5 -1.3 -0.4 -1.9 -4.3 1.6 0.1 -1.7 -4.6 -3.0 -1.1 -0.6 |-1.6 1.4 0.5 -2.0 0.8 -1.1 0.7 2.5 -4.2 -3.5 -6.3 -3.2 -3.2 -4.3 -7.1 -0.8 -2.9 -5.0 -0.6 0.3 0.4 -2.1 -3.2 -4.1 -3.8 -4.2 -2.2 -4.5 -2.2 1.3 -0.8 -3.9 -5.2 -0.3 -0.8 -2.9 -5.0 -3.0 -3.9 0.4 0.3 -3.1 -4.0 -3.7 4.0 -0.1 1.2 17 21 17 19

A random sample of 160 car accidents are selected and categorized by the age of the driver determined to be at fault. The results are listed below. The age distribution of drivers for the given categories is 18% for the under 26 group, 39% for the 26-45 group, 31% for the 45-65 group, and 12% for the group over 65. Find the rejection region used to test the claim that all ages have crash rates proportional to their number of drivers.

A clinical trial is run to assess the effects of different forms of regular exercise on HDL levels in persons between the ages of 19 and 29. Participants in the study are randomly assigned to one of three exercise groups—weight training, aerobic exercise, or stretching/yoga—and instructed to follow the program for 8 weeks.  Their HDL levels are measured after 9 weeks and are summarized below.   Exercise Group N Mean Std Dev Weight Training 20 49.7 10.2 Aerobic Exercise 20 43.1 11.1 Stretching/Yoga 20 57.0 12.5   Complete the following ANOVA table.               Source of Error Sums of Squares df Mean Squares F Between           Within 6157.32       Total                                 1.Write the hypotheses to be tested.   2. Write the decision rule. Please find the F for the closest df   3. What is the conclusion?

A researcher conducts a between-subjects study to determine whether low levels of the neurochemical serotonin leads to an increase in 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 receives a drug that lowers brain levels of serotonin. Using an alpha level of a = .05, the researcher then tests the animals by recording the number of aggressive responses each of the rats display. The data are as follows: a.) Step 1: State the Hypotheses Ho: H₁: Control n = 10 M = 14 SS=180.5 b.) Step 2: Determine the critical region and draw it on the distribution above: df = > *critical SM₁-M₂ Low Serotonin n = 15 M = 19 SS = 130.0 c.) Step 3: Calculate the test statistic using the provided sample data: tobs d.) Step 4: Make a decision. Circle one: Reject Null (Ho) or Fail to Reject Null (Ho) e.) State your conclusions about the research scenario in sentence form: d= f.) What is the estimated effect…

What test should I use for this problem?