Which of the following is the best formal definition of the statistical mode?

Given the quantitative responses recorded from a short test: [2, 3, 2, 5, 3, 2, 4, 2, 3], what is the mode?

A bar graph of preferred study locations among 100 students shows bars with heights: Library 40, Cafeteria 15, Dorm 25, Coffee Shop 20. Which category is the mode and why?

The following are the weekly paychecks in dollars for $16$ part-time tutors:

$650$, $720$, $880$, $950$, $1100$, $950$, $720$, $1050$, $980$, $880$, $950$, $1150$, $980$, $1050$, $950$, $1200$.

Determine the mean, median, and mode of these paychecks. Which value best represents a typical weekly paycheck?

A group of hikers recorded the distance they covered during a week. The recorded data (in kilometers) is as follows:

$7,9,11,12,14,15,17,18,20,21$

Compare the four measures of central tendency (mean, median, mode, and midrange) for the original data set and the $10\%$ trimmed data set.