Part 1

Length of Hospital Stay in Days for Robotic vs. Radical Surgery:

	Sample Mean	Sample Std. Dev.	Sample size
Robotic Surgery	1.2	0.7	160
Radical Surgery	3.5	0.6	260

1. Base on your hypothesis tests and confidence interval with 95%(s),pretend you are speaking with Jamal Johnstonand you are giving them recommendations as to which surgery (robotic/radical) would be better based solely on this data. What would you say to Jamal? Assume that Jamal knows nothing about statistics so Jamal doesn't have any experience with P-values or test statistics so "talk" in layperson terms.

Part 2

One can determine how old a tree is by counting its rings, but that Requires cutting the tree down. A forester wanted to investigate whether or not the age of a tree can be estimated simply from its diameter so they measured 27 trees of the same species that had been cut down, and counted the rings to determine the ages of the trees. The following are the data collected.

Diameter in inches	Age in years	Diameter in inches	Age in years	Diameter in inches	Age in years	Diameter in inches	Age in years
3.8	4	6.8	12	9.3	23	11.5	34
3.8	5	6.9	13	9.9	25	11.7	35
5.7	8	7.6	14	9.8	28	11.7	38
5.0	8	7.6	16	10.6	29	11.7	38
5.8	8	8.1	18	10.6	30	12.5	40
6.9	10	9.0	20	10.4	30	12.3	42
6.1	10	8.8	22	11.3	33

1. Graph this Best Fit linear model on the same graph as the scatterplot.

2. Explain what the slope of the regression line means in context of this problem.

3.Find the coefficient of determination, R², and explain what it means in the context of this problem. You need to address the percent variation in the response variable due to the explanatory variable.