Name: ____________________________
Histograms and Dot Plots
Histogram: 1. No gaps between bars 2. Bar width is the same along x-­‐axis 3. Y-­‐axis always gives the frequency (count) 4. Don’t forget to title the graph and label each axis *Create a frequency table to help you organize your data before graphing 1. On a test of eye-­‐hand coordination, the number of seconds required to finish a task involving fitting various shapes into corresponding holes is recorded. A group of 15 students in the second grade required the following times to complete the task. Coordination Scores (in seconds) 83 76 90 58 66 44 86 66 61 59 50 53 61 64 73 a. Construct a histogram (and label) that displays these results using intervals of 10. Intervals Frequency d. Looking at your histogram, what percent of students scored over 80? f. How would you describe the distribution? (SOCS) 2. The dot plot below shows the ages friends. e. Looking at the histogram, which interval would the median fall under? 3. The histogram shows how many pages the
students in Mr. Dean’s class read.
a. What is the median? b. What is the mean? a.
How many students w ere in his class? b. How many students read at most 99 pages? c.
Which interval would the median fall under? 4. The following frequency table displayed the scores students made on a recent math test. a. How many students were included in the data? Score Frequency b. What is the median of the data? 70 4 75 5 80 7 c. What is the mean of the data? 85 7 d. What percent of scored between a 75 and 80? 90 2 5. On the first three test Dirk has scores of 85, 90, and 75. What is the lowest possible score that Dirk can score on
the fourth test in order to have a mean of 85?
a. How m any of the students have at most 1 sibling? b.How m any of the students have no siblings? c. How m any of the students have three or more siblings?
7. Which statement is not true about the histogram below? 14
Number of families 12
Number of families
6. Students were asked how many siblings they each have. The dot plot shows the results. 10
8
6
4
2
0
0 - 2.
3 - 5.
6 - 8.
9 - 11.
Number of pets
(a) 12-­‐14 families have 2 pets (b) 33 families were surveyed (c) 13 families have at least 6 pets (d) 12 families have at m ost 2 pets 8. What terms do you use to describe shape? Sketch an example of each type of distribution 9. What helps you determine the shape of a distribution? 10. What do you look at when describing center? 11. What do you look at when you describe the spread? 12 - 14.