1.2djj.notebook
October 08, 2009
Section 1.2: Estimation and Graphs
Objective 2
Circle Graph (pie chart): shows how a whole quantity is divided into parts or sectors. Sectors are labeled with a name and %.
ex. The amount of electricity used in a typical all­electric home is shown in the circle graph. If a home used 1,100 kwh (kilowatt­hours) in a certain month, estimate the amount of electricity used by heating and air­conditioning.
Sep 18­10:21 AM
1
1.2djj.notebook
October 08, 2009
Bar Graph: similar to histogram, bars are horizontal or vertical.
ex. The bar graph shows the percentage of vacations that included the activity listed on the left.
Estimate the percentage of vacations that include shopping.
Estimate the percentage of vacations that include beaches.
In a group consisting of 800 randomly selected U.S. vacationers, estimate how many more vacations include shopping than beaches.
Sep 18­10:23 AM
2
1.2djj.notebook
October 08, 2009
Line Graph: similar to frequency polygon, use ~ to show a break on an axis
ex. The line graph shows the percentage of federal prisoners in the U. S. sentenced for drug offenses from 1970 through 2001.
a. For the period shown, in which year was the percentage of federal prisoners sentenced for drug offenses at a maximum? b. In which five­year period did the percentage increase at the greatest rate?
c. Given the number of federal prisoners in the U. S. in 1995 is 89,538, estimate the number of federal prisoners sentenced for drug offenses in that year.
See text ex. 6 ­ 8.
Sep 18­10:25 AM
3
1.2djj.notebook
October 08, 2009
Oct 8­10:40 AM
4