Real-World Applications of Percentages

This video series covers seventh grade illustrative mathematics, focusing on concepts like scaling, ratios, percentages, and measurement errors. Each lesson delves into specific mathematical principles, providing examples and problem-solving techniques to enhance understanding.

If a rectangle has a height-to-width ratio of 3:4.5, which of the following could be a scaled version of this rectangle?

• 12:15

• 9:12

• 6:9

• 15:18

A cyclist rode 3.75 miles in 0.3 hours. What was her speed in miles per hour?

• 12.5 mph

• 10 mph

• 17.5 mph

• 15 mph

If a bakery used 25% more butter this month than last month, and last month they used 240 kg, how much butter did they use this month?

• 320 kg

• 260 kg

• 280 kg

• 300 kg

A pair of sneakers was bought for $120 and its price increased by 15%. What is the new price?

• $130

• $135

• $138

• $140

If a circle's circumference is 600 meters, what is a good approximation of its area?

• 20,000 m²

• 25,000 m²

• 35,000 m²

• 30,000 m²

If a bakery used 560 kg of sugar last month and 30% more this month, how much sugar did they use this month?

• 728 kg

• 168 kg

• 560 kg

• 392 kg

What is the sales tax rate in Nevada if a $10 item has a sales tax of $0.46?

• 7.25%

• 5.125%

• 4.6%

• 6.5%

A store marks up a guitar by 30% and sells it for $58.50. What was the original price?

• $45

• $50

• $40

• $55

If a thermometer reads 331.5°F but the actual temperature is 325°F, what is the percentage error?

• 1.27%

• 1.6%

• 1.5%

• 2%

A student estimated a task would take 3 hours, but it took 5 hours. What is the percent error?

• 40%

• 30%

• 50%

• 60%