# Question Video: Comparing Track Length Using Box Plots Mathematics • 7th Grade

The box plots represent data collected on the length of recorded tracks from the top 100 rap and the top 100 heavy metal music charts. On average which genre of music has longer tracks? Compare the significance of the track length 4.40 minutes for the two music genres.

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### Video Transcript

The box plots below represent data collected on the length of recorded tracks from the top 100 rap and the top 100 heavy metal music charts. On average, which genre of music has longer tracks? And then compare the significance of the track length 4.40 minutes for the two music genre.

Well, if we take a look at part one first, the measure of average used in a box plot is the median, which is the vertical bar inside the box. Well, if we read down from our medians to the axis, we can see that the median track length for rap tracks is 4.00 minutes, whereas the median for heavy metal tracks is 4.80 minutes. And since the median for heavy metal tracks is higher than that for rap tracks, we can conclude that heavy metal tracks are on average longer than rap tracks.

Although it’s not part of this question, we could however also look at the spread of the track lengths. And if we did that, we would see that the range, which is the maximum value minus the minimum value, of rap tracks is in fact greater. So it has a greater spread of values. But also the IQR or interquartile range, which is Q three minus Q one, is also greater. So we can see actually that the differences of spread of the track lengths of rap tracks is greater than metal tracks.

Okay, so now let’s take a look at the second part of the question. Well, for the second part of the question, what we want to do is concentrate on the value 4.40 minutes. So if we take a look at what this means for rap tracks, well 4.40 minutes is where the right-hand vertical bar of the box sits. And what this represents is the value of Q three, our upper quartile, so the third quartile for rap. And what this means is that 75 percent of rap tracks are less than 4.40 minutes long and only 25 percent are in fact longer than 4.40 minutes long.

However, if we look at heavy metal tracks, 4.40 minutes represents Q one, so the lower quartile. And what this means is that 25 percent of heavy metal tracks are in fact shorter than 4.40 minutes long and 75 percent of them are longer than 4.40 minutes long. So, hence, what we can say about the significance of 4.40 minutes is that 75 percent of rap tracks are shorter than 4.40 minutes. However, 75 percent of heavy metal tracks are in fact longer than 4.40 minutes.