Use the births data set for questions $4-11$

$4.$ Perform vector operations

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

b$.$ What units do you think the weights are in$?$

c$.$ 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.

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

your word processing document