Practice subsetting the data frame you created in Exercise 2!
Open the R script that you used for Exercise 2, and re-run the code there to ensure that data is loaded into your current environment. Check that this worked properly by typing data and str(data) at the prompt and inspecting the output.
B.1 Use a logical index vector to locate the rows with females. Name this vector femaleIndex and use it to look at the entries of data with females. Also, use this vector and a logical operator to look at the rows of data with men. HINT: you may find the exclamation point ! useful.
B.2 What is the mean salary for females? Is it more or less than that of males? HINT: you may want to repeat step 1 for males, subset the column salary, and use the mean() function.
B.3 Is the mean salary an appropriate measure of the difference between the two groups? Compare their median salaries and comment. HINT: use the function median().
C.1 Look at the rows of data whose salaries are less than the mean salary.
C.2 Repeat step 1 using the median salary. Are there more or less people with salaries lower than the median versus salaries lower than the mean? Why do you think this is?
D.1 On average, do people with a high school education make less anually than people with bachelor’s degrees? Use the data to answer this question.
D.2 Does the proportion of women differ among people with a high school education and people with at least a bachelor’s degree? HINT: make a logical index vector to select people with a HS education (name it hs_index) and use the ! operator to select people with at least a BS. You can use the sum() function to get the total number of TRUEs from a logical index vector (e.g., the total number of poeple in the data frame with a high school education is sum(hs_index)).