Slides and Numericals on Whisker and Box Plots

Numericals on Box Plots

1. DMA_2_BoxPlots_Numericals By Prof. Mangal S. Dandekar

2. Q1 Suppose you have the math test results for a class of 15 students. Here are the results: 91 95 54 69 80 85 88 73 71 70 66 90 86 84 73 Sort the data Find median, Q1 and Q3 values. Find the extreme values. Min and Max. Find the Extreme values Find IQR Find Q3 + 1.5* IQR Find Q1 - 1.5 * IQR Find outliers

3. Five number summary Sorted data: 54 66 69 70 71 73 73 80 84 85 86 88 90 91 95 Extreme values = 54 and 95.

4. Plotted Box Plot For Q1

5. Interpretations from the box plot The box and whisker plot shows that 50% of the students have scores between 70 and 88 points. In addition, 75% scored lower than 88 points, and 50% have test results above 80.

6. Example 2 : comparative double box and whisker plot Suppose an IT company has two stores that sell computers. The company recorded the number of sales each store made each month. In the past 12 months, we have the following numbers of sold computers: Store 1 : 350, 460, 20, 160, 580, 250, 210, 120, 200, 510, 290, 380. Store 2: 520, 180, 260, 380, 80, 500, 630, 420, 210, 70, 440, 140.

7. The five-number summary The five-number summary for Store 1’s sales is 20, 180, 270, 420, 580. Using the same calculations, we can find that the five-number summary for Store 2 is 70, 160, 320, 470, 630

8. Interpreting the results: Store 2’s highest and lowest sales are both higher than Store 1’s relevant sales. In addition, Store 2’s median sales value is higher than Store 1’s. Also, Store 2’s interquartile range is larger. These results tell us that Store 2 consistently sells more computers than Store 1.

9. Q3 on Box Plot

10. Q3 Solution

11. Box Plot Quiz https://www.thatquiz.org/tq/preview?c=rncmsa4b&s=nj87z8