Lesson s 3.2 An al yzi n g an d Com par i n g St at i st i cal Gr aph s WARM- UP

Transcription

1 Nam e: Dat e: Lesson s 3.2 An al yzi n g an d Com par i n g St at i st i cal Gr aph s WARM- UP 1. Place the point on the number line that corresponds to each given value. A. 2 B. -28 C D. 40 E Find the difference between 1.5 thousand and The set of real numbers (integers) includes all numbers and all numbers. 4. numbers are those that have or decimals.

2 REINFORCINGKEYIDEAS Numerical dat a can be displ ayed in. Bar graphs use and bars t o represent dat a. Expl orat ion 1 A sampl e survey asked st udent s t o name t heir f avorit e t ype of pet. The resul t s are shown in t he bar graph bel ow. a. What information is shown on the vertical axis? The horizontal axis? b. Use the graph to complete the table. Pet Number of Students c. How many students were surveyed? d. Anal yze: Which pet did students choose twice as often as the hamster? Explain

3 Exampl e 1: Int erpret ing Doubl e-bar Graphs Sal and Harry bot h own sandwich shops. The doubl e-bar graph shows t he number of shops t hey owned at t he end of each year. What concl usions can be made f rom t he graph? a. always had more shops open than, except in 2004, when they both had the number of shops open. b. The number of shops Harry owned from the years to c. The number of shops Sal owned from the years 2001 to, but from the years to.

4 Exampl e 2: Int erpret ing St em-and-leaf Pl ot s The stem-and-leaf plot shows the ages of members of a hiking club. Find the age of members at the hiking club that occurs most often. Sol ut ion Look at the key. The stems represent and the leaves represent. So 3 2 represents 3 tens and 2 ones. The data set for this plot is: Which value occurs most often?. What does this mean? Ext ension: Make a stem and leaf plot of the ages of everyone in the class:

5 Exampl e 3: Int erpret ing Line and Doubl e-l ine graphs The double-line graph shows the same data as the double-bar graph in Example 1. What conclusions can you make from each graph? Sol ut ion Sal had sandwhich shops than Harry in 2001, but in they both had the same number of sandwich shops. The graph of Harry's shops is a line that shows a steady in the number of shops each year. Harry had more shops than Sal in, the both had shops in 2004, and had 11 more shops than in 2006.

6 Exampl e 4: Comparing Dat a using Doubl e-bar Graphs The table shows Andre's bank account tansactions Mont h January February March April May June Deposit s $475 $200 $350 $425 $500 $150 $100 $275 $350 $400 $200 $225 Wit hdrawal s On a separate piece of paper, make a graph to compare deposits and withdrawals. Label the axes and include a key. Sol ut ion Use a double-bar graph to compare the deposits and withdrawals. The graph shows that the were greater than the withdrawals in January, April, and. The withdrawals were greater than the deposits in and. Andre deposited and withdrew the same amount of money in.

7 Exampl e 5: Appl icat ion: Yearl y Sal es A graph uses sections of a to compare parts of the circle to the whole circle. The whole circle represents the entire set of data. The circle graph below shows Art Online's total yearly sales by quarter. The total amount of sales for the year was $20 million. Find the sales for each quarter. Sol ut ion Multiply the percent of sales for each quarter by the total amount for the year. 1st Quarter: 2nd Quarter: 3rd Quarter: 4th Quarter: Check Find the sum of the amounts calculated for each quarter.

8 Lesson Pract ice 1. Use the double-bar graph in Example 1. What year shows the greatest difference between the number of shops Sal and Harry owned? 2. Use the double-line graph in Example 3. What was the greatest number of shops Sal opened in one year? 3. a. Make a stem-and-leaf plot of the data showing the height in inches of grandchildren in the Jones family: 56, 52, 68, 49, 40,72, 71, 43, 54. Label all parts of the plot. b. What height occurs most often? 4. Heal Uset hythe data in Example 4. Which month shows the greatest difference between deposits and withdrawals? 5. Use the circle graph from Example 5. If first quarter sales the next year are $3,000,000- can you predict the sales for the year?