1. You want to know how livable urban residents find their city to be, and decide that it is too complex a concept to be captured by a single variable or question. Instead, you decide to create an additive index. You decide to focus on the following four questions: ************************************** Overview i.) Do you spend more than 25% of your income on housing? - no - yes ii.) Do you commute more than 20 minutes to work or school? - no - yes iii.) Do you have to travel over 2 miles from your home in order to get to a public library? - no - yes iv.) Do you have to travel over .5 miles in from your home in order to get to a public park or green space? - no - yes ************************************** The above data set is made up of 4 variables: INCOME, TRAVEL, LIBRARY, PARK. Each of the four variables has two possible responses (No or Yes)