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Problem of the Week
Problem A and Solution
Missing Data


Jasmine created a circle chart and a bar chart based on data values, but forgot what numbers went with which chart. The charts are shown below. There are five values in total, two belong to the circle chart and three belong to the bar chart.

Here are the values: V: \(30\), W: \(40\), X: \(60\), Y: \(120\), Z: \(180\)

Label each chart with the letters matching the appropriate values. Then add values to the scale on the vertical axis of the bar chart.


Comparing the size of the sections in the circle chart, we see that the smaller section appears to be one quarter of the whole circle and the larger section appears to be three quarters of the whole circle. This means the larger section is three times the size of the smaller section. Comparing the heights of the bars, we can see that the tallest bar is three times the height of the leftmost bar. We should look at the data to find pairs of numbers where one number is three times the other number.

From the values listed we see that \(3 \times 40 = 120\) and \(3 \times 60 = 180\). So the circle chart values could be either \(120\) and \(40\) or \(180\) and \(60\).

Based on this logic, the leftmost bar represents the value \(40\). The top of the bar matches the second grid line. Since the grid lines are equally spaced, we can conclude that the distance between grid lines is \(40 \div 2 = 20\).

Here is the labelled bar chart:

Here is the labelled circle chart: