Question

Which box-and-whisker plot matches the data? 28,29,29,31,34,39,41,46,47,49,52,54

Answer 1

The first step when you want to graph the data points into a box and whisker plot, arrange the data points from lowest to highest:

28,29,29,31,34,39,41,46,47,49,52,54

Next, find the median of the data. This is the middle value. Since it contains an even number of 12, take the average of the 2 middle values.

Median = (39+41/2 = 40

Now, divide the data down to the middle. The groups would be:

28,29,29,31,34,39  and 41,46,47,49,52,54

Now, take the median of each group. For the lower half, the median is equal to (29+31)/2 = 30. For the upper half, the median is equal to (47+49)/2 = 48.

Therefore, the box starts from 30 and ends at 48. Then, a line is drawn in between at the median 40. Then, the whiskers are added by drawing lines from the lowest at 28 to the start of the box at 30, and from the end of the box at 48 to the highest value at 54.

Hence, the box and whisker plot for this data is letter A or the first choice.