Final answer:
To construct a box-and-whisker plot, plot the minimum, Q1, median, Q3, and maximum on a number line and draw a box from Q1 to Q3 with 'whiskers' to the minimum and maximum. The interquartile range (IQR) for the provided data is 3.
Step-by-step explanation:
To construct a box-and-whisker plot, also known as a box plot, you need five key values: minimum, first quartile (Q1), median (Q2), third quartile (Q3), and maximum. For the given data, these are 12, 15.5, 17, 18.5, and 22, respectively.
- Draw a number line that includes the smallest and largest values of your data set.
- Mark the minimum value (12) and the maximum value (22) on the number line.
- Draw a box from the first quartile (15.5) to the third quartile (18.5).
- Within this box, draw a line at the median value (17).
- Draw 'whiskers' from the ends of the box to the minimum and maximum values.
To calculate the interquartile range (IQR), subtract the first quartile from the third quartile:
IQR = Q3 - Q1
IQR = 18.5 - 15.5
IQR = 3
The interquartile range is 3, indicating the range of the middle 50% of the data.