A school’s yearbook committee had many meetings last month the line plot summarizes how long each meeting lasted

On the graph, it shows that the shortest meeting has lasted for 1/4 of an hour. An hour has 60 mins, you know it the shortest will be 15 minutes.
If its for any other number that you do not know, you can list as a proportion:
1/4 = x/60 (1 and x are on the top of the fractions)
Cross multiply: 1 * 60 = 60
Then divide by the number on the opposite corner of x: 60/4
x = 15