Question

The price per share of Power​ Company's stock over 9​ days, rounded to the nearest​ dollar, is below. Use a box plot to determine how many dollars greater per share the third quartile price was than the first quartile price. 20, 8, 10, 24, 12, 12, 14, 16, 22

Answer 1

The third quartile price is $10 per share greater than the first quartile

Explanation:

To draw a box plot, we need a series of things;

These are;

1. Minimum value

2. Maximum value

3. Median

4. 1st quartile

5. 3rd quartile

To find all of these before we plot our box plot, we need to rearrange the values in the data set from lowest to highest;

That will be;

8,10,12,12,14,16,20,22,24

There are 9 members of the data set.

The minimum value is 8, the maximum value is 24

The median is the middle value which is the 5th term

The fifth term here is 14

The formula for the first quartile is:

(n + 1)/4

where n is the number of terms which is 9 here.

The 1st quartile will be;

(9 + 1)/4 = 10/4 = 2.5

This is approximately the 3rd term and it is 12 from our arrangement

The 3rd quartile is;

3(n + 1)/4 = 3 * 10/4 = 7.5

The 3rd quartile is the 8th term which is 22

Hence, the third quartile is greater than the first quartile with the value 22-12 = 10