Archie is fed up with waiting in line at his local post office and decides to take action. don't understand this whatsoever.

Question 3 of 12 (1 point) | Question Attempt: 1 of 1 Archie is fed up with waiting in line at his local post office and decides to take action. Over the course of the next few months, he records the waiting times for each of a random selection of 25 post office visits made by him and other customers. These waiting times (in minutes) are summarized in the following histogram. Frequency Waiting time (in mrutes) Based on the histogram, find the proportion of waiting times in the sample that are less than 12 minutes. Write your answer as a decimal, and do not round your answer. X