CK-12-Basic Probability and Statistics Concepts - A Full Course

(Marvins-Underground-K-12) #1

http://www.ck12.org Chapter 7. Organizing and Displaying Data


From looking at the tops of the bars, you can see how many winners were in each category, and by adding these
numbers, you can determine the total number of winners. You can also determine how many winners were within a
specific category. For example, you can see that 8 winners were 60 years of age or older. The graph can also be used
to determine percentages. For example, it can answer the question, “What percentage of the winners were 50 years
of age or older?” as follows:
16
30 =^0.^533 (^0.^533 )(100%)≈^5 .3%.


Guided Practice


a. Use the data and the distribution table that represent the ages of teachers from Example B to construct a histogram
to display the data. The distribution table is shown again below:


TABLE7.15:


Bin Tally Frequency
[ 0 − 5 ) ||||||||| 11
[ 5 − 10 ) |||||||| 9
[ 10 − 15 ) |||||||||| 12
[ 15 − 20 ) |||||||||||| 14
[ 20 − 25 ) |||||| 7
[ 25 − 30 ) |||||||| 10
[ 30 − 35 ) |||||||||| 12

b. Now use the histogram to answer the following questions.


i. How many teachers teach in this small town?


ii. How many teachers have worked for less than 5 years?


iii. If teachers are able to retire when they have taught for 30 years or more, how many are eligible to retire?


iv. What percentage of the teachers still have to teach for 10 years or fewer before they are eligible to retire?


v. Do you think that the majority of the teachers are young or old? Justify your answer.

Free download pdf