Can you please show work by hand and all hypothesis steps.

1. A study examined the effects of amphetamine on bar pressing for food in rats using four groups: placebo; 1 mg/kg; 2 mg/kg; and 4 mg/kg. Assume equal samples sizes, random selection, and random assignment of subjects to each group.

(a) What is the experimental design for this study?

(a2) Complete the summary table below:

Source SS df MS F p

Drug (BG)

Error (WG) 485

Total 1028 47

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(b) Show the hypotheses, alpha level, decision rule, and state your conclusions for this study.

(c) Would you follow-up this analysis with a post-hoc test? Why or why not? What additional information would you need in order to perform the test?

2. (a) Draw a frequency distribution graph using the following measures of central tendency and indicate (approximately) where they are on the graph.

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X = 20 Mode = 35 Median = 28

(b) Describe the shape of this distribution.

(c) Which measure of central tendency would best represent this distribution? Why?

(d) Which measure of variability should be used? Why?

3. A researcher is interested in the relationship between the number of hours that students work each week and their grades. The collected data are shown below:

Hours Worked (X) GPA (Y)

10 3.2

0 2.8

12 3.5

3 2.6

8 2.9

19 3.5

(a) Calculate the correlation coefficient for these data? Show ALL formulas and calculations.

(b) Determine if this correlation is significant or not. Show ALL formulas and calculations. Show the hypotheses, alpha level, decision rule, and state your conclusions for this study.