Answer:
101
Step-by-step explanation:
The first step is to extract the data from the stem and leaf given. From the stem and leaf, the stem is 2-digits value and leaf follows.
Here are the stems:
11, 21, 31, 41 and 51.
The leaves are:
6, 2, 4, 8, 9, 0, 1, 1, 2, 3, 4, 5, 6, 7, 8, 1, 5, 8, 0, 1, 8.
Therefore the actual data become:
116, 212, 214, 218, 219, 310, 311, 311, 312, 313, 314, 315, 316, 317, 318, 411, 415, 418, 510, 511, 518.
Having done this, we calculate the IQR. The IQR is known as Interquartile range which is the difference between the upper quartile and the lower quartile.
That is,
IQR = Q3 - Q2
You can simply do this in R:
#.........R code
stm = c(116, 212,214,218,219,310,311,311,312,313,314,315,316,317,318,
411,415,418,510,511,518)
quantile(stm) #... this gives you the quartiles.
IQR(stm) #.. this gives the answer directly
