In that distribution, which class interval contains the median value?

In that distribution, which class interval contains the median value?

• A. 5-9
• B. 10-14
• C. 15-19
• D. 20-24

Answer: (C)

The concept being tested is locating the median in a grouped frequency distribution. To do this, you find the 50th percentile by taking half of the total number of observations and then summing the class frequencies from the smallest interval upward until you reach or pass that halfway point. The class interval where that halfway point falls is the median class—the interval that contains the median value. In this distribution, the halfway point falls inside the 15-19 interval, so the median value lies within that class. If you wanted a precise median, you could use interpolation within that interval, but the key point is that the 50th percentile is reached somewhere in 15-19.

The concept being tested is locating the median in a grouped frequency distribution. To do this, you find the 50th percentile by taking half of the total number of observations and then summing the class frequencies from the smallest interval upward until you reach or pass that halfway point. The class interval where that halfway point falls is the median class—the interval that contains the median value.

In this distribution, the halfway point falls inside the 15-19 interval, so the median value lies within that class. If you wanted a precise median, you could use interpolation within that interval, but the key point is that the 50th percentile is reached somewhere in 15-19.