1. Purpose: To solve problems solving percents. Homework: p. 317 -319 1-21 odd and problems 1-15 odd.

2. Formula Whenever a price is changed you can find the percent of increase or decrease by the following: Percent of change = change in price 1000 original price To find the change in price, you calculate the difference between the original price and the new price.

3. Examples Alyce originally paid $6500 for a ca 3 years ago. The same car costs $7400 today. What is the change in price? Find the change in price by subtracting $6500 from $7400. $7400 – $6500 = $900 The price increased $900

4. Example #2 The Bakers’ real estate taxes went from $1560 to $1683. What was the percent of increase? Let x = the percent of increase. % of Change = change in price 100 original x = 78 **Cross Products. 100 1560 1560x = 7800; x = 5; 5% increase

5. Example #3 The number of registered voters in Fresno increased by 14% over last year. There are now 9633 registered voters. How many voters were there last year? Let x = the # of voters last year. 9633 – x will = the change in # of voters. 14 = 9633 – x ** Cross Products. 100 x 14x = 100(9633 – x) 14x = 963300 – 100x 114x = 963300 x = 8450; There were 8450 voters last year.

6. Joe invested $2000 at 51/4% annual interest and $3000 at 8 ½% annual interest. What percent interest is he earning on his investment? A + B = Total.0525(2000) +.085(3000) = 5000x 10000[.0525(2000) +.085(3000) = 5000x]10000 525(2000) + 850(3000) = 50,000,000x 1,050,000 + 2,550,000 = 50,000,000x 3,605,000 = 50,000,000x ; x =.072 ; 7.2% Amt. Invested RateInterest Invest A2000.0525. 0525(2000) Invest B3000.085.085(3000) Total5000x5000x