A math teacher is comparing math project scores from two classes. She wants to compare the medians and ranges of the scores from both sets of data.
Which display should the math teacher use?
scatter plots
dot plots
histograms
box plots
Is it dot plots
Yes, I would use a dot plot, see:
https://www.youtube.com/watch?v=McFY7kT25FQ
thanks
It was wrong
I think its histograms
Well, a histogram will work.
The two dot plots below compare the forearm lengths of two groups of schoolchildren:
Two dot plots are shown one below the other. The title for the top dot plot is Forearm Length, Group X and the title for the bottom plot is Forearm Length, Group Y. Below the line for each dot plot is written Length in inches. There are markings from 10 to 13 on each line at intervals of one. For the top line there are 4 dots above the first mark, 4 dots above the second mark, and 2 dots above the third mark. For the bottom line there are 2 dots above the second mark, 2 dots above the third mark, and 6 dots above the fourth mark.
Based on the visual inspection of the dot plots, which group appears to have the longer average forearm length? (5 points)
Group X, because no child in the group has a forearm length longer than 12 inches.
Group X, because four children in the group have the least forearm length of 10 inches.
Group Y, because a child in the group has the least forearm length of 10 inches.
Group Y, because six children have a forearm length longer than 12 inches.
Group Y, because six children in the group have a forearm length longer than 12 inches, indicating a longer average forearm length compared to Group X.
Kim wants to know if the number of words on a page in her math book is generally more than the number of words on a page in her poetry book. She takes a random sample of 25 pages in each book, then calculates the mean, median, and mean absolute deviation for the 25 samples of each book.
Book Mean Median Mean absolute deviation
Math 49.9 43 10.2
Poetry 41.5 42 1.1
Kim claims that because the mean number of words on each page in the math book is greater than the mean number of words on each page in the poetry book, the math book has more words per page. Based on the data, is this a valid inference? (5 points)
No, because there is a lot of variability in the math book data
No, because the mean is larger in the math book
Yes, because the mean is larger in the math book
Yes, because there is a lot of variability in the math book data
No, because there is a lot of variability in the math book data, as indicated by the larger mean absolute deviation. The mean alone is not always a reliable measure of central tendency when there is a lot of variability in the data.
To compare the medians and ranges of the scores from both sets of data, the math teacher should use a box plot.
A box plot displays the five-number summary of a dataset - the minimum, first quartile, median, third quartile, and maximum values. The median is represented by a line across the box plot, while the range is determined by the whiskers that extend from the minimum to the maximum values.
By using a box plot, the math teacher can easily compare the medians (by comparing the positions of the median lines) and ranges (by noting the distance between the minimum and maximum values) of the scores in both classes. This graphical display provides a clear visual representation of the distribution and spread of the data, making it suitable for comparing important statistics like medians and ranges.