Data Inspection:

$($a$)(1$pt$)$ How many observations are there in the dataset? Also, give the line or lines of $R$ code used to find this answer.

$($b$)(1$pt$)$ For each variable, how many missing entries are there? Also, give the line or lines of $R$ code used to find this answer.

$($c$)(1$pt$)$ Using the sort$()$ function, find the height of the tallest and shortest individuals. Also, give the line or lines of $R$ code used to find this answer.

$($d$)(1$pt$)$ Using the order $()$ function, order the data according to the Income variable from largest to smallest. What is the largest income in the dataset? Also, give the line or lines of $R$ code used to find this answer.