Lesson 4: Represent and Describe Data in a Box Plot6.DS.5

I can…

I can make and read a box plot to summarize a data set.

Key words

• Display Data with Box Plots — Show a data set's five-number summary in a box-and-whisker display.
• Box Plot — A graph that shows how data is spread using five key numbers.
• Median — The middle number when you put them in order.
• Quartile — Numbers that split the data into four equal parts.
• Interquartile Range — The spread of the middle half of the data (Q3 − Q1).
• Data distribution — How the data looks: where it sits and how spread out it is.
• Variability — How spread out the numbers are.
• Five-number summary — The minimum, first quartile, median, third quartile, and maximum of a data set.
• Whisker — A line on a box plot that reaches from the box out to the least or greatest value.
• Middle half — The values from the first quartile to the third quartile, which the box covers.

Steps

1. My data, in order: 4, 6, 8, 10, 12, 14, 15, 18, 22, 24, 28. There are 11 numbers.
2. The middle number is the 6th one, 14, so the median = 14.
3. The lower half is 4, 6, 8, 10, 12. Its middle is 8, so Q1 = 8.
4. The upper half is 15, 18, 22, 24, 28. Its middle is 22, so Q3 = 22.
5. The lowest is 4 and the highest is 28. I draw a box from 8 to 22, a line at 14, and whiskers out to 4 and 28.

Try it

Now find the five-number summary for a DIFFERENT team — the Comets: 2, 6, 10, 12, 16, 18, 22, 24, 26, 30, 34.

Check your answer

Check with your guided notes.

Sentence starter

I know ___ because ___.

Goal: I can explain my box plot using the words box plot, median, quartile, and interquartile range.