Problem 11
The stem represents the tens digit and the leaves are the units digit.
Here is each row of data from the stem and leaf plot
31, 34, 39,
20, 20, 24, 25, 27, 28, 28,
10, 13, 14, 14, 15, 17, 17
Which is the same as this when written as all one line
31, 34, 39, 20, 20, 24, 25, 27, 28, 28, 10, 13, 14, 14, 15, 17, 17
Optionally we can sort the values so it will be helpful later on
10, 13, 14, 14, 15, 17, 17, 20, 20, 24, 25, 27, 28, 28, 31, 34, 39
There are 17 values in that list above, so there are 17 chapters.
Answer: 17
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Problem 12
There are 10 pages in the shortest chapter, as this is the minimum of the data list. Refer back to problem 11.
Answer: 10
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Problem 13
max = 39
min = 10
range = max-min = 39-10 = 29
range = 29
Answer: 29
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Problem 14
The sample size is n = 17, so n/2 = 17/2 = 8.5 which means 8 values are below the median and 8 values are above the median.
The median is in slot 9. So count out 9 spaces in this list
10, 13, 14, 14, 15, 17, 17, 20, 20, 24, 25, 27, 28, 28, 31, 34, 39
and you should see that the median is 20
Answer: 20
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Problem 15
Focus on the last 8 values, which are above the median 20 (in slot 9)
24, 25, 27, 28, 28, 31, 34, 39
Find the median of that data subset
You should find that the median here is 28
Therefore, the third quartile is 28
Answer: 28
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Problem 16
Focus on the first 8 values
10, 13, 14, 14, 15, 17, 17, 20
The median is exactly halfway between 14 and 15, so it is (14+15)/2 = 14.5, which is the value of Q1.
Answer: 14.5
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Problem 17
The box and whisker plot is shown below.
The tip of the left whisker is the min = 10
The left edge of the box is Q1 = 14.5
The vertical line inside the box is the median = 20
The right edge of the box is Q3 = 28
The tip of the right whisker is the max = 39
