Exercise

# Test for a difference in median test scores

The High School and Beyond survey is conducted on high school seniors by the National Center of Education Statistics. We randomly sampled 200 observations from this survey, and these data are in the `hsb2`

data frame (which is already loaded for you). Among other variables, this data frame contains scores on `math`

and `science`

scores of each sampled student.

Instructions 1/4

**undefined XP**

Add a column to `hsb2`

named `diff`

containing the `math`

scores minus the `science`

scores.