7-6 Percent of Change

Transcription

1 Find the percent of change. Then state whether the percent of change is an increase or decrease. Round to the nearest tenth, if necessary. 1. From $40 to $32 20%; decrease 2. From 56 inches to 63 inches 12.5%; increase 3. FINANCIAL LITERACY On Saturday, Smoothie Central made $1300 in sales. On Sunday, they made $900 in sales. What is the percent of change from Saturday to Sunday? about 30.8%; decrease Find the selling price for each item given the cost and the percent of markup. 4. shoes: $30, 25% markup $ CD player; $45, 31% markup $ BIKES Find the sale price of a bike that is regularly $110 and is on sale for 45% off the original price. $60.50 Find the percent of change. Round to the nearest tenth, if necessary. Then state whether the percent of change is an increase or decrease. 7. From 14 inches to 26 inches 85.7%; increase 8. From $36 to $ %; increase 9. From 82 feet to 74 feet 9.8%; decrease esolutions Manual - Powered by Cognero Page 1

2 10. From 16 kilograms to 5 kilograms 68.8%; decrease 11. From $128 to $ %; decrease 12. From 90 yards to 72 yards 20%; decrease 13. From 191 ounces to 270 ounces 41.4%; increase 14. From 150 minutes to 172 minutes 14.7%; increase 15. GASOLINE A survey of gas prices in January showed that the cost per gallon one year was $ The following January, the cost per gallon was $ Find the percent change in gas prices from one year to the next to the nearest tenth. 13.2%; increase 16. FOOTBALL Jerome High School s football team scored 38 points in their first game. The next week they only scored 17 points. Find the percent change in the number of points scored by the football team to the nearest tenth. 55.3%; decrease Find the selling price for each item given the cost and the percent of markup. 17. video game: $60; 28% markup $ bracelet: $26.50, 35% markup $ jacket: $25; 32% markup $33.00 esolutions Manual - Powered by Cognero Page 2

3 20. stereo: $55, 40% markup $ wallet: $14.50, 30% markup $ phone: $34, 36% markup $ television; $499, 20% markup $ mountain bike: $255, 34% mark up $ SALONS A salon is having a sale on their hair products. Find the sale price of the shampoo and conditioner set shown below that regularly costs $10. $ ENTERTAINMENT The unlimited rental plan at a video store costs $30 a month. It is on sale for 35% off the original price. What is the sale price of the plan? $19.50 esolutions Manual - Powered by Cognero Page 3

4 27. TELEVISION For the local telethon 3860 viewers called in and donated money on the first night. The next night, there was a 20% decrease in the number of calls from the first night. How many calls did the telethon receive on the second night? 3088 calls 28. OLYMPICS There were 10,651 athletes who participated in the 2000 Summer Olympics in Sydney, Australia. In the 2004 Summer Olympics in Athens, Greece, 11,099 athletes participated. What was the percent of change in the number of athletes participating from 2000 to 2004? Round to the nearest tenth. 4.2%; increase 29. BICYCLING According to the National Sporting Goods Association, the number of people who participated in bicycle riding in 2004 was 40.3 million. In 2006, the number was 35.6 million. Find the percent of change from 2004 to Round to the nearest tenth. 11.7% 30. DOGS Kyla s boxer weighs about 62 pounds. When it was a puppy it only weighed 23 pounds. What is the percent of change in we. Round to the nearest tenth % 31. TRACK Torie s 400 meter dash time is 74 seconds. Juliette s time is 15% faster than Torie s. What is Juliette s 400 meter dash time? Write an inequality comparing the two times. Use the symbols < or > s; 62.9 < BUSINESS The first and second quarter earnings of two restaurants are shown at the right. Which restaurant had the greater percent of change in the second quarter? B; It increased by 22% and restaurant A increased by about 3%. esolutions Manual - Powered by Cognero Page 4

5 33. MULTIPLE REPRESENTATIONS In this problem, you will compare percents of change. The table shows the population of capital cities for four different states. a. Tabular Copy and complete the table. Round to the nearest whole percent. b. Analytical Compare the amounts of change and the percents of change for Columbia and Columbus. Explain the differences and similarities between the two. a. b. Sample answer: The percents of change were the same but the amount of change for Columbus was much greater than the amount of change for Columbia. The percents were the same because the original amounts for each city were very different. esolutions Manual - Powered by Cognero Page 5

6 34. MULTIPLE REPRESENTATIONS In this problem you will examine percent of change over time. The table gives the price of milk for various years. a. Algebraic Write two inequalities comparing the percent of increase from 1970 to 1980 to the percent of increase from 1980 to Round to the nearest percent, if necessary. b. Graphical Graph the prices of milk over the years. Use the x-axis as the years and y-axis as the prices. c. Graphical Use the graph to determine which decade had the greatest percent of increase in the price of milk. Explain your reasoning. a. 30% < 34%; 34% > 30% b. c ; The graph is steeper during that time. 35. OPEN ENDED Give an example of a percent of increase. Sample answer: from 80 mi to 160 mi; 100% increase 36. CHALLENGE An item at a consignment shop is marked down 10% each week until it sells. If a bicycle was originally priced at $150, what is the cost after 3 weeks? 6 weeks? $109.35; $79.72 esolutions Manual - Powered by Cognero Page 6

7 37. REASONING Determine whether each statement is true or false. If false, provide a counterexample. a. It is impossible to increase the cost of an item by more than 100%. b. It is possible to decrease the cost of an item by less than 1%. a. false; Sample answer: An item costs $25 and you want to mark it up 125%. Multiply $25 by 125% or The new price is $25 + $31.25 or $ b. true 38. CHALLENGE Suppose a store has an item on sale for 25% off the original amount. By what percent does the store have to increase the price of the item in order to sell the item for the original amount? Explain. 33 %; Sample answer: Suppose the cost of the item is $100. So, 25% of $100 is $25 and $100 $25 = $75. Then set a proportion to find what percent of $75 is $25. $75 p % = $25. Solve for p : =. p = 33 % 39. WRITING IN MATH Write and solve a real-world problem involving a discount of an item. Sample answer: An internet service provider offers a plan for $40 per month. If this month the plan is 45% off, what is the cost of the plan?; $ If each dimension of the rectangle is tripled, what is the percent of increase in the area? A 300% B 600% C 800% D 900% C 41. Which of the following represents the greatest percent of change? F Boots that were originally priced at $90 are on sale for $63. G A baby that weighed 7 pounds at birth now weighs 10 pounds. H A bracelet that costs $12 to make is sold for $28. J A savings account increased from $500 to $600 in 1 year. H esolutions Manual - Powered by Cognero Page 7

8 42. The table shows the annual budget of a city. Which statement is supported by the table? A The budget decreased and then increased. B The greatest percent of change occurred from 2009 to C The budget increased 20% from 2011 to D The percent of change from 2009 to 2010 was the same as from 2010 to C 43. GRIDDED RESPONSE The price of a television was $900 on Tuesday. On Wednesday the manager reduced the price 5%. What was the price of the television after the reduction? 855 Solve each problem using the percent equation. 44. Find 12% of Find 42% of What is 37.5% of 89? What is 24.2% of 60? FOOD Suppose fifty-six percent of the Calories in corn chips are from fat. If one serving contains 160 Calories, estimate the number of Calories from fat in one serving of corn chips. about 90 Calories esolutions Manual - Powered by Cognero Page 8

9 49. FISH Of the fish in an aquarium, 26% are angelfish. If the aquarium contains 50 fish, how many are angelfish? angelfish Find each sum. Write in simplest form Write each fraction as a decimal esolutions Manual - Powered by Cognero Page 9

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