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Ratio, Percent, Proportion. EQ: How do you use standard ratio notation for expressing ratios? (3:5, 3 to 5, 3/5) OBJ: 1.01 . Ratio:. A ratio is a comparison of two numbers by division
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Ratio, Percent, Proportion EQ: How do you use standard ratio notation for expressing ratios? (3:5, 3 to 5, 3/5) OBJ: 1.01
Ratio: • A ratio is a comparison of two numbers by division • If a gallon of paint contains 2 parts blue paint and 4 parts yellow paint, then the ratio comparing blue paint to yellow paint would be 2 to 4, 2 : 4, 2/4 • REMEMBER to simplify when possible 2/4 = ½ • 9 goldfish out of 15 fish • 9/15 3/5 *This means that for every 5 fish, 3 of them are goldfish Express the ratio as a fraction
IMPORTANT • When writing a ratio involving measurements, both quantities should have the same unit of measurement. • 3 feet to 16 inches 3feet convert to inches 36 inches 16 inches 16 inches Simplify 9 inches 4 inches 9 to 4 Express the ratio as a fraction
Rate: • A rate is a ratio of two measurements having different kinds of units. 65 miles in 3 hours $16 for 2 pounds • When a rate is simplified, so that it has a denominator of 1, it is called a unit rate. • An example of a unit rate is $5 per pound, which means $5 per 1 pound Unit Rate
Find and compare unit rates • A package of 20 recordable CDs costs $18, and a package of 30 recordable CDs costs $28. Which package has the lower cost per CD? 18 dollars = 0.9 dollars 20 CDs 1 CD for the 20-pack, the unit rate is $0.90 per CD. 28 dollars = 0.93 dollars 30 CDs 1 CD for the 30-pack, the unit rate is $0.93 per CD So, the package that contains 20 CDs has the lower cost per CD
Convert Rates • A grizzly bear can run 30 miles in 1 hour. How many feet is this per second? *You need to convert 30 mi to Xft. 1 hr 1 sec **There are 5,820 feet in 1 mile and 3600 seconds in 1 hour. • 30mi. = 30 mi * 5280 ft ÷ 3600 s 1 hr 1 hr 1 mi 1 hr Cancel out and multiply across = 44 ft 1 sec So, 30 miles per hour is equivalent to 44 feet per second