1. Create a text vector called Months with names of the 12 months of the year.

2. Create a numeric vector Summer, with Calendar month index positions for the summer months (inclu-

   sive, with 4 elements in all).

3. Use vector indexing to extract the text values of Months, indexed by Summer.

4. Multiply Summer by 3. What are the values of Months, when indexed by Summer multiplied by 3? Why do you get that answer?

5. What is the mean (average) summer month, as an integer value? Which value of Months corresponds to it? Why do you get that answer?

6. Use the floor() and ceiling() functions to return the upper and lower limits of Months for the average Summer month. (Hint: to find out how a function works, use R help if needed.)

7. Using the data below, how many visits did Berts store have?

   1. store.num <- factor(c(3, 14, 21, 32, 54)) # store id store.rev <- c(543, 654, 345, 678, 234) # store revenue, $1000 store.visits <- c(45, 78, 32, 56, 34) # visits, 1000s store.manager <- c("Annie", "Bert", "Carla", "Dave", "Ella") (store.df <- data.frame(store.num, store.rev, store.visits, store.manager, stringsAsFactors=F))

Answer using Program R