# Video: Reporting the Number of Observations in a Data Set in a Line Plot

The line plot represents the number of hours that a group of people spent exercising in a week. How many people were in the group?

01:42

### Video Transcript

The line plot represents the number of hours that a group of people spent exercising in a week. How many people were in the group?

Well in a line plot, the đť‘Ą-axis contains all the different categories. And in this case, that represents the number of hours of exercise that they did, so either one hour or two hours or three hours or four hours or five hours.

And the number of crosses that you see against each of those categories tells you about the frequency, so how many people within the group said they did that number of hours. So for example, one person said they did one hour, three people said they did two hoursâ€™ exercise, four people said they did three hoursâ€™ exercise, only one person said they did four hoursâ€™ exercise, and two people said they did five hoursâ€™ exercise.

So we can see from that that the most popular category was to do three hours; four people did three hours; thatâ€™s more than any other particular number of hours. And the least popular, well one and four, so fewer people did one than any other category and fewer people did four hoursâ€™ exercise than any other category.

Now the question says how many people were in the group? And to find out that answer, we need to add up all these numbers: the one person who did one hours plus the three people who did two hoursâ€™ exercise plus the four people who did three hours plus the one who did four hours plus the two people who did five hours.

And if I add up those numbers, I get eleven people. So the answer is, there were eleven people in the group.