Question

Suppose you know the minimum, lower quartile, median, upper quartile, and maximum values for a set of data. Explain how to create a box plot for the data set.

NO LiNKS OR BE REPORTED

Answer 1

First, create a scale that includes all the numbers- that being, you can plot both the minimum and maximum values on it.

Next, draw a line of a set height (I tend to use 2 squares in my work) where the median is. Next, draw similar lines, at the same height, for the rest of the values- both quartiles and the maximum values. You can obviously do this in whatever order you like, but that's how I do it.

Next, join up the tops and bottoms of the quartiles, with the median in the middle, and connect the middles of the quartiles to their corresponding minimum or maximum values.

Voila, my friend. You have a box plot.

Explanation:

First, create a scale that includes all the numbers- that being, you can plot both the minimum and maximum values on it.

Next, draw a line of a set height (I tend to use 2 squares in my work) where the median is. Next, draw similar lines, at the same height, for the rest of the values- both quartiles and the maximum values. You can obviously do this in whatever order you like, but that's how I do it.

Next, join up the tops and bottoms of the quartiles, with the median in the middle, and connect the middles of the quartiles to their corresponding minimum or maximum values.

Voila, my friend. You have a box plot.

Answer 2

For some sets of data, some of the largest value, smallest value

, first quartile, median, and third quartile may be the same. For instance, you might have a data set in which the median and the third quartile are the same. In this case, the diagram would not have a dotted line inside the box displaying the median. The right side of the box would display both the third quartile and the median. For example, if the smallest value and the first quartile were both one, the median and the third quartile were both five, and the largest value was seven, the box plot would look like:

In this case, at least

25

25

% of the values are equal to one. Twenty-five percent of the values are between one and five, inclusive. At least

25

25

% of the values are equal to five. The top

25

25

% of the values fall between five and seven, inclusive.