Saturday, July 11, 2015

Use the following stem-and-leaf plot, representing the starting salary (in thousands of dollars) of ten friends after college graduation, to complete problems 30 through 37. 1 | 7 9 2 | 0 1 3 3 4 3 | 0 3 4 | 0 Key: 1 | 7 = 17 List the values from the stem and leaf plot in numerical order. What is the mode of this distribtuion? What is the mean of this distribution? Explain how you would find the media. What is the median for this set? Explain how you would find the lower quartile. What is the lower quartile for this set? Explain how you would find the upper quartile. What is the upper quartile for this set?

For a stem and leaf plot, the number to the left of the bar is generally the stem and the numbers to the right of the bar are the leaves. The stem is the first digit(s) and the leaves are the next significant digit. The leaves are not separated by commas.
For this plot the data are 17,19,20,21,23,23,24,30,33,40
Note that the key tells us that 1|7 is 17. (It could have been 170 if the key was 1|7=170 or .17 if the key had been 1|7=.17 etc...)
Since there are 10 data items the median is the arithmetic mean of the 5th and 6th numbers of the ordered list -- here the median is 23. The mode is the number(s) that occur the most often -- here the mode is 23.
To find the mean we add the numbers and divide by 10 (the number of elements).
The lower quartile is the median of the lower half (the first 5 elements) and is 20 while the upper quartile is the median of the upper half which is 30.
http://mathworld.wolfram.com/Stem-and-LeafDiagram.html

No comments:

Post a Comment

Why is the fact that the Americans are helping the Russians important?

In the late author Tom Clancy’s first novel, The Hunt for Red October, the assistance rendered to the Russians by the United States is impor...