Understanding Proportions

This video tutorial covers the concepts of ratios, rates, and proportions. It begins with definitions and examples of ratios and rates, explaining how they are used to compare quantities. The tutorial then delves into solving proportions using cross multiplication, providing step-by-step examples. Finally, it applies these concepts to a real-life problem involving the recommended daily allowance of protein based on body weight.

What is a ratio?

• A number that represents a part of a whole

• A mathematical statement that two rates are equal

• A quotient of two quantities with the same unit

• A comparison of two quantities with different units

How can a rate be expressed?

• As a quotient of two quantities with different units

• As a whole number

• As a decimal

• As a fraction with the same units

What is a proportion?

• A comparison of two quantities with the same unit

• A statement that two ratios or rates are equal

• A number that represents a part of a whole

• A fraction with different units

What is the property of proportions regarding cross products?

• Cross products are always greater than one

• Cross products are always zero

• Cross products are always equal

• Cross products are always different

In the proportion 3/4 = x/8, what is the value of x?

• 6

• 12

• 9

• 8

How do you solve for a variable in a proportion?

• By cross-multiplying and solving the equation

• By adding the cross products

• By dividing the cross products

• By subtracting the cross products

If 2/3 = 4/x, what is the value of x?

• 8

• 7

• 6

• 5

What is the RDA of protein for adults per kilogram of body weight?

• 1.0 grams

• 0.8 grams

• 0.5 grams

• 1.2 grams

How many grams of protein should a 150-pound person consume daily?

• 50 grams

• 54.5 grams

• 60 grams

• 45 grams

What is the first step in solving a proportion problem involving body weight and protein intake?

• Set up a ratio

• Set up a rate

• Set up a proportion

• Set up a fraction