Load data

1. Using the variable “sleptim1” and “marital”, determine the following:

1.1 number of observations that are “NA” in the variable “sleptim1”;

1.2 number of observations having at most 5 hours of sleep;

1.3 number of observations having more than 5 hours of sleep but less than 11 hours of sleep;

1.4 number of observations having at least 11 hours of sleep and

1.5 number of observations having at most 5 hours of sleep that are married.