Question

On R-studio

Run the following starter code first. This will load the relevant datasets and libraries.

install.packages("car")

install.packages("reshape2")

library(car); library(reshape2)

data(Salaries)

library(ggplot2); library(lm.beta)

Construct a scatter plot with yrs.service on the x-axis, salary on the y-axis,represent rank using color and draw lines through the points. Hint: Lookup up geom_point, geom_smooth at http://docs.ggplot2.org/current/. If you are unable to figure it out, you may run this code.

ggplot(data=Salaries,aes(x=yrs.service,y=salary,color=rank)) + geom_point() +  geom_smooth(method="lm",size=1.1,se=F)

Now, answer the following questions:

A. With years of service, salary of Assistant Professors

		A. goes down
		B. remains the same
		c.  goes up

B. Using the plot constructed for the last question, answer the following question:

With years of service, salary of Associate Professors

		A. goes down
		B. remains the same
		C. goes up

C. Using the plot constructed for the last question, answer the following question:

With years of service, salary of Professors

		A. goes down
		B. remains the same
		C. Goes up

Answer 1

Answer for Question A: option c

With years of service, salary of Assistant Professors goes up.

From the plot we can see the red line, which has +ve slope. which means increasing

Answer for Question B: option A

With years of service, salary of Associate Professors goes down

From the plot we can see the green line, which has -ve slope. which means increasing

Answer for Question c: option B

With years of service, salary of Professors remains the same

From the plot we can see the blue line, which is nearly parallel to x -axis, which means it remains same