Question: Based on the data in the stem and leaf plot, find the sum of the average of lower quartile and the middle quartile and the average of middle quartile and the upper quartile.
A ) 50 B ) 40 C ) 43 D ) 44
Steps to derive
1 The data values in the stem and leaf plot are 10, 11, 14, 17, 18, 20, 24, 27, 32, 36 and 38. [Attach each value of the leaf with its corresponding stem.]
2 Middle quartile of the data is 20. [Middle value of the entire data set.]
3 Lower quartile is 14. [Middle value of the lower half of the data set.]
4 Upper quartile is 32. [Middle value of the upper half of the data set.]
5 Average of the lower and the middle quartiles = 14+202 = 342 =17 [Sum of lower and middle quartiles divided by 2.]
6 Average of the middle quartile and the upper quartiles = 20+322 = 522 = 26 [Sum of the middle and the upper quartiles divide by 2.]
7 Sum of the two averages = 17 + 26 = 43 [Add 17 and 26.]
