Power Point Slides
5 Number Summary:
The five number summary gives you a rough idea about what your data set looks like. for example, you’ll have your lowest value (the minimum) and the highest value (the maximum). Although it’s useful in itself, the main reason you’ll want to find a five-number summary is to find more useful statistics, like the interquartile range, sometimes called the middle fifty.
How to Find a Five-Number Summary: Steps
- Step 1: Put your numbers in ascending order (from smallest to largest). For this particular data set, the order is:
- Step 2: Find the minimum and maximum for your data set. Now that your numbers are in order, this should be easy to spot.
In the example in step 1, the minimum (the smallest number) is 1 and the maximum (the largest number) is 27.
- Step 3: Find the median. The median is the middle number. If you aren’t sure how to find the median, see: How to find the mean mode and median.
- Step 4: Place parentheses around the numbers above and below the median.
(This is not technically necessary, but it makes Q1 and Q3 easier to find).
- Step 5: Find Q1 and Q3. Q1 can be thought of as a median in the lower half of the data, and Q3 can be thought of as a median for the upper half of data.
(1,2,5,6,7), 9, ( 12,15,18,19,27).
- Step 6: Write down your summary found in the above steps.
minimum=1, Q1 =5, median=9, Q3=18, and maximum=27.