Percents and Constant of Proportionality

Vocabulary How does a percent relate to a proportion? Drag the words to complete the explanation.

Each word may be used once or not at all.

A percent is a ________ of proportionality describing the ______

of the ________.

• A percent is a constant of proportionality describing the part of the whole.

• A percent is a variable of proportionality describing the whole of the part.

• A percent is a constant of proportionality describing the whole of the part.

• A percent is a variable of proportionality describing the part of the whole.

Sewing patterns recommend buying extra fabric in case of mistakes. Jessica bought 6 yards of fabric, plus 20% extra fabric.

Derek bought 4 yards of fabric, plus 25% extra. Who bought more fabric? How much more?

• Jessica, 2 1/5

• Jessica, 2

• Derek, 2 1/5

• Derek, 4

Lou and Jacob each sold 150 pieces of jewelry. If 20% of Lou’s sales were rings, and Jacob sold 25 rings, who sold more rings? How many more?

• Lou sold more rings. He sold 100 more rings than Jacob.

• Jacob sold more rings. He sold 5 more rings than Jacob.

• Lou sold more rings. He sold 5 more rings than Jacob.

• Jacob sold more rings. He sold 15 more rings than Lou.

List the correct answers in order with the percentage symbol!

• 80%, 5%, 33.3%, 15%

• 80%, 95%, 33.3%, 15%

• .8, .5, .333, .15

• 80% 95% 33% 15%

Rabbit Population

The rabbit population in a certain area is 200% of last​ year's population. There are 900 rabbits this year. How many were there last​ year?

• 1800 rabbits

• 450 rabbits

• 0.22 rabbits

• 200 rabbits

A company that makes​ hair-care products had 8,000 people try a new shampoo. Of the 8,000 ​people, 12 had a mild allergic reaction. What percent of the people had a mild allergic​ reaction?

 In a survey of 2,500 people who owned a certain type of​ car, 1,520 said they would buy that type of car again. What percent of the people surveyed were satisfied with the​ car?

The local newspaper has 30 letters to the editor from people. If this number represents 5% of all of the​ newspaper's readers, how many readers does the newspaper​ have?