Questions: The students in a first-grade class were all asked to time how long (in seconds) they could hold their breath. The results were tallied and are presented in the following histogram. How many of those students held their breath for less than 11.5 seconds?

Solution Steps

The problem asks how many students held their breath for less than 11.5 seconds. The data is presented in a bar graph showing the frequency of students for different time intervals.

Identify the bars on the graph that represent times less than 11.5 seconds. These intervals are:

• 7.5 to 8.5 seconds
• 8.5 to 9.5 seconds
• 9.5 to 10.5 seconds
• 10.5 to 11.5 seconds

Count the frequencies for each of these intervals:

• 7.5 to 8.5 seconds: 2 students
• 8.5 to 9.5 seconds: 1 student
• 9.5 to 10.5 seconds: 4 students
• 10.5 to 11.5 seconds: 3 students

Final Answer