1. GRAPHS & FORMULAS PAGES 167 - 200 Chapter 6

2. To find an average (or arithmetic mean) add all the quantities to be averaged (if a quantity is repeated, then it must be added that many times to find the average) then divide by the total number of quantities. Pages 169 – 170 & 175

3. To find the median first arrange the numbers in order from the smallest to the largest The median is the number in the middle If there are two numbers in the middle, the median is the average of the two. Pages 171 – 172

4. To find the mode list the numbers in order from the smallest to the largest The mode is the number that appears the most number of times. Page 173

5. Look at the scale to find the measurement for each bar. If a bar ends between marks, estimate between numbers on the scale. Pages 176 – 177

6. Draw two perpendicular lines for your graph. Measure and mark off distances at even intervals. Draw the bars neatly. Be sure the bars are the right length. Page 178

7. Read the title of the graph to find out what the information is about. Look carefully at the vertical scale to learn what each level means. Read the legend to gather more information (if there is one) Page 179

8. Give your graph a title. Choose a scale that will allow you to fit everything on the graph. Page 180

9. A circle graph gives a picture of different percentages. You can get information about comparisons with a quick look. For your homework – exercises involving computation, read the question carefully and then study the graph for the necessary information. Pages 181 – 182

10. For your homework The mileage between two cites will be found by following rows across and columns down from those two cities. Where the two meet, you will find the distance. Page 183

11. In a formula, letters take the place of numbers. When letters are next to each other, it means multiplication. If you know all but one of the variables in a formula you can substitute in the values to find the missing variable. d = rtdistance = rate x time i = prtinterest = principal x rate x time Pages 184 – 186

12. A ratio is simply a comparison of two things by division. A ratio looks like a fraction Page 187

13. If you want to find a unit rate, that goes with one of something (1 day, hour, quart, gallon, and so forth), divide both numbers in the ratio by the denominator. In other words a unit rate is when the denominator is 1 Page 188

14. A proportion is an equality of two ratios. Be sure each fraction or ratio is set up in the same way For example: Pages 189 – 192 mi gal mi gal = Solve by cross multiplying

15. For something that happens only once, the probability of any particular result is the fraction showing all the favorable results out of all the possible ones. Page 193

16. For something that happens more than once, you can predict the number of favorable outcomes. Multiply the probability of the event by the number of repetitions. Page 194

17. If two events do not affect each other, find the probability that both will happen by multiplying the probabilities of each event. Page 195

18. If two events do affect each other, use the result of the first event to help find the probability of the second. Page 196