Q: If a stock increases from $$104.33 to 112.21$$, what is the percent change? (Round to the first decimal place.)

$$\frac{112.21 - 104.33}{104.33} \times 100 \approx 7.6\%$$

Q: A city’s population increased from 50,000 to 55,000 in one year. What is the percent change?

$$\frac{55,000 - 50,000}{50,000} \times 100 = 10\%$$

Question 1

A university student is comparing tuition costs. If the average annual charge for tuition and fees at a public four-year college is $$9970 and at a public two-year college is 3570$$, what is the unit ratio of four-year to two-year tuition, and what does it mean?

Accepted Answer

$$9970 \div 3570 = 2.79$$; the four-year college is 2.79 times as expensive as the two-year college.

Question 2

Which of the following best describes a unit ratio?

Accepted Answer

A ratio written as $$\frac{a}{b}$$ with $$b = 1.$$

Question 3

Given the following data for median sales price and median household income in the Midwest: $$269,700$$ and $$54,267$$, respectively, what is the unit ratio of sales price to income?

Accepted Answer

$$\frac{269,700}{54,267} \approx 4.97$$

Question 4

If the median sales price of homes is lower in the South than in the Midwest, but the median income is also lower in the South, which region is more affordable and why?

Accepted Answer

The Midwest is more affordable because the unit ratio of sales price to income is lower.

Question 5

Convert 7% to a decimal.

Accepted Answer

0.07

Question 6

Convert 0.125 to a percentage.

Accepted Answer

12.5%

Question 7

A person buys a guitar for $1500 in a state with a 7% sales tax. How much is the sales tax?

Accepted Answer

$$0.07 	imes 1500 = 105$$

Question 8

If a stock increases from $$104.33 to 112.21$$, what is the percent change? (Round to the first decimal place.)

Accepted Answer

$$\frac{112.21 - 104.33}{104.33} 	imes 100 \approx 7.6\%$$

Question 9

Which of the following statements is correct regarding percent change when comparing two investments with different starting values?

Accepted Answer

Percent change is more meaningful than absolute change when comparing investments with different starting values.

Question 10

What is the product of $$-5$$ and $$-6$$?

Accepted Answer

30

Question 11

Find the product: $$7 	imes (-4).$$

Accepted Answer

-28

Question 12

Which of the following is true about multiplying or dividing two real numbers?

Accepted Answer

The product or quotient of two numbers with different signs is negative.

Question 13

Calculate $$\left(-\frac{3}{2}ight) 	imes \left(-\frac{5}{7}ight).$$

Accepted Answer

$$\frac{15}{14}$$

Question 14

Find the quotient: $$-10 \div 2.$$

Accepted Answer

-5

Question 15

Which of the following is equivalent to $$-\frac{a}{b}$$, where $$b 
eq 0$$?

Accepted Answer

$$-\frac{a}{b} = \frac{a}{-b} = -\frac{a}{b}$$

Question 16

A city’s population increased from 50,000 to 55,000 in one year. What is the percent change?

Accepted Answer

$$\frac{55,000 - 50,000}{50,000} 	imes 100 = 10\%$$

Question 17

If $$a = 0.86$$, what is $$a as a $$percentage?

Accepted Answer

86%

Question 18

Which of the following best describes the meaning of percent?

Accepted Answer

$$a\% = \frac{a}{100}$$

Ratios, Percents, and Operations with Real Numbers: Foundations for Statistical Analysis

스터디 가이드 - 연습 문제

학습 가이드 - 플래시카드