Exam 4: Exponential Functions

One solution to the equation 4 + x = 4(2)^x is x = 0. Use your calculator to estimate the other solution to 2 decimal places.

Kathleen opens a savings account with $1600. The account earns 3.6% annual interest compounded quarterly. How much will be in the account after 12 years?

In some developing countries, the inflation rate has been as high as 0.78% per day. What is the corresponding percent annual inflation rate? Round to the nearest whole number.

What is the balance after 10 years in an account containing $600 that earns 4% interest compounded monthly? Round to the nearest cent.

The populations of 4 species of animals are given by the following equations: What is the annual percent growth rate for the population that is growing the fastest?

The price of an item increases due to inflation. Let Give the price of the item as a function of time in years, with t = 0 in 2004. What is the practical interpretation of ?

Is the formula for a function representing a quantity which begins at an amount 35% larger than N in year t = 0 and grows at a continuous annual rate of r% given by ?

The populations of 4 species of animals are given by the following equations: What is the smallest initial population of the 4 species?

The figure below shows the graphs of the following functions: (A) (B) (C) (D) Which one is the graph of D?

How much interest is earned in an account yielding 4.2% annual interest compounded weekly if the initial investment is $1000 and the money stays in the account for 20 years?

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The following figure shows two functions, one linear and the other exponential. The formula for the linear one is , and the formula for the exponential one is . Round the first two answers to 2 decimal places and the last two answers to 3 decimal places.

The following figure gives the graph of , where C is the computer hard disk capacity (in hundreds of megabytes) that could be bought for $500 t years past 1989. If the trend displayed in the graph continued, how many megabytes would a $500 hard drive have in 1999? Round to the nearest hundred.

Is the formula for a function representing a quantity which begins at N in year t = 0 and grows at a constant annual rate of r% given by ?

Jeff has $^20,000.He placed $10,000 in Bank 1 with an account earning 3.1% annual interest, compounded continuously. He also placed $10,000 in Bank 2 with an account earning 3.7% annual interest compounded weekly. After 10 years, A) how much money is in Bank 1? B) how much money is in Bank 2?

Write a verbal description for each of the following formulas. The units are dollars and years.

A quantity increased from 20 to 24. By what percentage did it increase?

An investment grows according to the formula . How many years will it take for the original investment to quadruple? Round to 1 decimal place.

Each of the functions in the table below is increasing, but each increases in a different way. One is linear, one is exponential, and one is neither. The formula for the exponential one is . Round your second answer to 2 decimal places.