Tell whether the shape of each of these population distributions would be leftskewed/low outliers, right-skewed/high outliers, fairly symmetric but non-normal, or approximately normal:
a. Age of people who made their first visit to a dentist in a particular year
b. Number of fillings for U.S. college students
c. Length of adults' incisor teeth d. Number of teeth (their own) retained by Americans in their sixties