130 likes | 306 Views
Box and Whisker Plots. Box and Whisker Plot. A box and whisker plot is a diagram or graph that shows quartiles and extreme values of a set of data. Five Number Summary. Median LQ (Lower Quartile) UQ (Upper Quartile) Minimum Maximum. Let’s review how to find the Five Number Summary….
E N D
Box and Whisker Plot A box and whisker plot is a diagram or graph that shows quartiles and extreme values of a set of data.
Five Number Summary • Median • LQ (Lower Quartile) • UQ (Upper Quartile) • Minimum • Maximum
Let’s review how to find the Five Number Summary… Here are the number of gold medals won by the top 16 countries in the 1992 summer Olympics.
First, put the numbers in order from least to greatest. 3, 3, 4, 5, 6, 6, 7, 8, 11, 12, 13, 14, 16, 33, 37, 45 5.5 LQ 9.5 Med 15 UQ Min Max Second, find the median, lower quartile (LQ), and upper quartile (UQ). Third, find the minimum & maximum. Min = 3 LQ = 5.5 Med = 9.5 UQ = 15 Max = 45 This is called a “five number summary.”
To draw the box and whisker plot, you need the five number summary. Min = 3 LQ = 5.5 Med = 9.5 UQ = 15 Max = 45 First, draw a number line that will accommodate the data range.
0 5 10 15 20 25 30 35 40 45 50 LQ, Med, and UQ form the box. The “whiskers” connect the box with the minimum and maximum. You have just drawn a box and whisker plot!
0 5 10 15 20 25 30 35 40 45 50 Box and whisker plots are divided into quartiles. Each quartile contains 1/4 or 25% of the data. Even though the quartiles do not appear to be equal, they all contain an equal amount of data. For this box and whisker plot... 1st fourth of data: x < 5.5 2nd fourth of data: 5.5 < x < 9.5 3rd fourth of data: 9.5 < x < 15 4th fourth of data: x > 15
0 5 10 15 20 25 30 35 40 45 50 Using the box and whisker plot: What percent of the teams won 6 and 15 gold medals? About 50% What does the plot tell us about the upper half of the data compared to the lower half? The upper half is more spread out while the lower half is closely clustered together.
Here is the time in which 10 students ran a mile: 10, 12, 8, 10, 9, 10, 9, 11, 10, 18 Find the “five number summary” and draw a box and whisker plot of the data. Click when you are ready for the answer.
8, 9, 9, 10, 10, 10, 10, 11, 12, 18 Min LQ 10 Med UQ Max Five Number Summary: Min = 8 LQ = 9 Med = 10 UQ = 11 Max = 18 7 8 9 10 11 12 13 14 15 16 17 18 19
There are more examples of box and whisker plots in your book. Happy graphing!