Ecological Correlation

In the second survey of Stat 100 in Fall 2013, students reported the number of hours they worked per week and the percent of their tuition their parents paid for. Download the data here and then load it to R using the following command.

survey <- read.csv("stat100_2013fall_survey02.csv")

The hours students work per week is in the column named "workHr" and the percent of tuition is in the column "tuition".

a. What is the correlation between workHr and tuition? Give your answer to 2 decimal places.

r =

Calculate the average of workHr for each ethnic group (given in the column ethnicity).

b. Which group has the highest average workHr?
Hispanic
Black
Mixed_Other
White
Asian

This highest average workHr is (round to 2 decimal places) hours/week

c. Which group has the lowest average workHr?
Black
White
Hispanic
Asian
Mixed_Other

This lowest average workHr is (round to 2 decimal places) hours/week

d. Calculate the average of tuition for each ethnic group. Then compute the correlation between the group means of workHr and the group means of tuition. This is known as the ecological correlation, as you have learned in Stat 100. Round your answer to 2 decimal places.

r_ecological =

e. The ecological correlation computed in part (d) is less negative more negative than the correlation computed in part (a).