# Percentage, Fraction and Growth Rates

Section 1.2

Diversification. Helen has of her portfolio in U.S.stocks, of her portfolio in European stocks, and of her portfolio in Japanese stocks. The remainder is invested in municipal bonds. What fraction of her portfolio is invested in municipal bonds? What percent is invested in municipal bonds?

Section 1.3

Net worth. Melanie's house is worth $125,000, but she still owes $78,422 on her mortgage. She has $21,236 in a savings account and has $9,477 in credit card debt. She owes $6,131 to the credit union and figures that her cars and other household items are worth a total of $15,000. What is Melanie's net worth?

Section 1.5

Population of Mexico. In 2004 the population of Mexico was 106.5 million. If Mexico's population continues to grow at an annual rate of 1.43%, then the population in 2015 will be million.

a) Find the predicted population in 2015 to the nearest tenth of a million people.

b) Use the result of Exercise 125 (see below) (Result: a. 330.2 million) to determine whether United States or Mexico will have the greater increase in population between 2004 and 2015.

Section 1.6

Forensics. A forensic scientist uses the expression 72.6 + 2.5T to estimate the height in centimeters of a female with a tibia of length T centimeters. If a female skeleton has a tibia of length 32.4 cm, then what was the height of the person? Find the length of your tibia (use a random value to solve it) in centimeters, and use the expression from this exercise or the previous exercise to estimate your height.

Exercise 106

Crop circles. The expression gives the area of a circle with radius r. How many square meters of wheat were destroyed when an alien ship made a crop circle of diameter 25 meters in the wheat field at the Southwind Ranch? Find on your calculator.

Exercise 106

Recovering golf balls. Susan and Joan are diving for golf balls in a large water trap. Susan recovers a golf ball every 0.016 hour while Joan recovers a ball every 0.025 hour. If both are working, then at what rate (in golf balls per hour) are they recovering golf balls?

Exercise 108

Farmland conversion. The amount of farmland in the United States is decreasing by one acre every 0.00876 hours as farmland is being converted to nonfarm use (American Farmland Trust, www.farmland.org). At what rate in acres per day is the farmland decreasing?

Section 1.8- Page 70

Exercise 114

Marriage penalty eliminated. The value of the expression

3910 + 0.25 (x - 28,400)

is the 2003 federal income tax for a single taxpayer with taxable income of x dollars, where x is over $28,400 but not over $68,800.

a) Simplify the expression.

b) Find the amount of tax for a single taxpayer with taxable income of $40,000.

c) Who pays more, a married couple with a joint taxable income of $80,000 or two single taxpayers with taxable incomes of $40,000 each?

#### Solution Summary

There are about 8 problems about Percentage, fraction and growth rates. Step by step explaination is provided sothat student is able to understand the concepts.