In my last post with Measures of Central Tendency I mentioned Inter Quartile Range and I wanted to show you just how we use those numbers and what they mean.
We use our Measures of Central Tendency to find the IQR Inter Quartile Range which is a measure of statistical dispersion, being equal to the difference between the 75th and 25th percentiles, or between the upper and lower quartiles. We use a Box and Whisker Plot as an explanatory data analyses, its basically a type of graph that shows spread/distribution of data. Using our data from Grab a Handful Activity we are going to continue to analyse data by making a Box and Whisker Plot.
The first thing we are going to do is order the data from least to greatest and make a number line with that range from the least to greatest numbers.
Now we need to find the Median (middle number) (also know as Q2). We know from our Measures of Central Tendency the Median is 10 so we are going to draw a line to represent the Median.
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| Median is showed in pink. Also is Q2 |
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| Add Ordered Data #'s 235 and divide by 22 to get Mean |
Next we are going to make draw 2 lines that represent the Minimum = MIN and Maximum = MAX
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| Min and Max lines then we will complete the box. |
Now we need to find the Lower Quartile and we do this by looking at the data on the lower half below the median which is 7 7 7 8 8 9 9 10 10 10 10. We take these 11 numbers and do the same to them as we do when finding the median of the whole data set to find the middle number and that would be a 9. The #9 is Q1 the 1st Quartile. We do the same to find the Upper Quartile but use the numbers 10 11 11 11 12 12 13 15 15 15 15, the middle number is a 12. The #12 is Q3 the 3rd Quartile.
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| Q1 and Q3 are shown in Blue and box is completed |
Most of the class picked between 7 and 10 within the 1st 50% of data set
Range: 8
Min: 7
Max: 15
Median: 10
Q1: 9
Q3: 12
I loved you showing pictures on how to make a box and whisker plot. That is sometimes better than instructions. I also loved how at the end you put down all your information. You did a great job at explaining everything as well. A very good job.
ReplyDeleteI tend to be more of a visual learner when it comes to things such as this that are more procedural and I love how you included illustrations for each step. You did such an outstanding job of making sure that all of your work was clear and provided a verbal explanation as well. Great job!
ReplyDeleteHi Terri,
ReplyDeleteWow great examples! I really liked how you used pictures and went through the whole steps. I was able to follow along and grasped the whole process. Even the colors and creativity was really good. Great job this is something to look back on to help students in the near future.
-Natalia Macias