1.During the worst periods of hyperinflation in a certaincountry, the price of food increased at a rate of 25% per month. State whether this increase was linear or exponential. If your food bill was $120 in one month during thisperiod, what was it three monthslater?

Was the growth in inflation linear orexponential?

linear

exponential

What was the monthly food bill after threemonths?

$

1. (Round to the nearest dollar asneeded.)

3.The initial population of a town is 3600, and it grows with a doubling time of 10 years. What will the population be in 8 years?

What will the population be in 8 years?

______

(Round to the nearest whole number asneeded.)

4.Use the approximate doubling time formula(rule of70) for the case described below. Discuss whether the formula is valid for the case described.

Gasoline prices are rising at a rate of 0.7% per month. What is their doublingtime? By what factor will prices increase in 2 years? in 10 years?

What is its doublingtime?

_____

months

(Type an integer or decimal rounded to the nearest hundredth asneeded.)

By what factor will the prices increase in 2 years?

____

(Type an integer or decimal rounded to the nearest hundredth asneeded.)

By what factor will the prices increase in 10 years?

____

(Type an integer or decimal rounded to the nearest hundredth asneeded.)

Is this formula valid in the casedescribed?

No, the given growth rate is above15%

No, the given growth rate is below15%

Yes, the given growth rate is below15%

Yes, the given growth rate is above15%

5.Thehalf-life of a radioactive substance is 25 years. If you start with some amount of thissubstance, what fraction will remain in 75 years? What fraction will remain in 125 years?

The fraction that will remain in in 75 years is the following.

______

(Simplify youranswer.)

The fraction that will remain in in 125 years is the following.

____

(Simplify youranswer.)

6.Thehalf-life of a drug in the bloodstream is 14 hours. What fraction of the original drug dose remains in 48 hours? in 60 hours?

What fraction of the original drug dose remains in 48 hours?

_____

(Do not round until the final answer. Then round to the nearest hundredth asneeded.)

What fraction of the original drug dose remains in 60 hours?

______

(Do not round until the final answer. Then round to the nearest hundredth asneeded.)

Use the approximatehalf-life formula for the case described below. Discuss whether the formula is valid for the case described.

Poaching is causing a population of elephants to decline by 4% per year. What is thehalf-life for thepopulation? If there are10,000 elephantstoday, how many will remain in 50 years?

What is thehalf-life for thepopulation?

________________

years (Type an integer or adecimal.)

If there are10,000 elephantstoday, how many will remain in 50 years?

_______

(Round to the nearest whole number asneeded.)

Does the approximatehalf-life formula give a valid approximation in the casedescribed?

Yes

No

8.Decide whether each of the following statements makes sense(or is clearlytrue) or does not make sense(or is clearlyfalse). Explain your reasoning.

The carrying capacity of our planet depends only on ourplanet's size.

Choose the correct answer below.

A.

The statement does not make sense because there are many factors that affect the carrying capacity that are not related to the size of the planet.

B.

The statement makes sense because all the factors involved in the carrying capacity can be related to the size of the earth.

C.

The statement does not make sense because the carrying capacity depends only on the size of the earth and the current human population.

D.

The statement does not make sense because the carrying capacity does not depend on the size of the earth.

9.Use an annual growth rate of 0.6% in a 20 year period for a certain population to find the approximate doubling time and then predict the population in2050, based on a 2000 population of 6.0 billion.

What is the approximate doublingtime?

_____

years

(Round to the nearest whole number asneeded.)

What will be the approximate population in2050?

___

billion

(Round to the nearest tenth asneeded.)

Assume the carrying capacity of the earth is 24 billion. Use the 1960s peak annual growth rate of 2.1% and population of 3 billion to predict the base growth rate and current growth rate with a logistic model. Assume a current population of 6.8 billion. How does the predicted growth rate compare to the actual growth rate of about 1.2% peryear?

What is the base growthrate?

____

% (Round to four decimal places asneeded.)

What is the estimated current growthrate?

_____

% (Round to two decimal places asneeded.)

How does the estimated growth rate compare to the actual current growthrate?

A.

The predicted growth rate is the same as the actual growth rate.

B.

The predicted growth rate is smaller than the actual growth rate.

C.

1. The predicted growth rate is larger than the actual growth rate.

10.Consider a student loan of $10,000 at a fixed APR of 11% for 4 years.

a. Calculate the monthly payment.

b. Determine the total amount paid over the term of the loan.

c. Of the total amountpaid, what percentage is paid toward the principal and what percentage is paid for interest.

a. The monthly payment is $

____

.

(Do not round until the final answer. Then round to the nearest cent asneeded.)

b. The total amount paid over the course of the loan is $

_____

.

(Round to the nearest cent asneeded.)

c. Of the total amountpaid,

______

% is paid toward the principal and

____

% is paid for interest.

(Round to once decimal place asneeded.)

11.

Consider the following pair of loan options for a $135,000 mortgage. Calculate the monthly payment and total closing costs for each option. Explain which is the better option and why.

Choice1: 20-year fixed rate at 4.5% with closing costs of $2600 and 1 point.

Choice2: 20-year fixed rate at 4.25% with closing costs of $2600 and 3 points.

What is the monthly payment for choice1?

$

_____

(Do not round until the final answer. Then round to the nearest cent asneeded.)

What is the monthly payment for choice2?

$

_____

(Do not round until the final answer. Then round to the nearest cent asneeded.)

What is the total closing cost for choice1?

$

____

What is the total closing cost for choice2?

$

____

Why might choice 1 be the betterchoice?

A.

The closing costs are lower.

B.

The monthly payment is higher.

C.

The closing costs are higher.

D.

The monthly payment is lower.

Why might choice 2 be the betterchoice?

A.

The closing costs are lower.

B.

The closing costs are higher.

C.

The monthly payment is lower.

D.

The monthly payment is higher.