$2.$ Work with the births data set.

a$.$ Extract the weight variable as a vector from the data frame.

b$.$ The original unit of weight is ounce. Create a new vector named weights$\_$in$\_$pounds which

are the weights of the babies in pounds. You can look up conversion factors on the internet.

Demonstrate your success by typing weights$\_$in$\_$pounds$[1$:$20]$ and including the output in

your word processing document.