### Carry Over Balance, Minimum Payment & Certificate of Deposit CD, Finance Charge

The key terms in this Mathematics course include Carry Over Balance, Minimum Payment, Finance Charge, Balance, Model, Certificate of Deposit – CD, Graph, Demogorgon Population, Exponential Model, Mold Spores,

You carry over a balance of $400 on a recent purchase of a washing machine, you will just pay the minimum payment each month for the next three months. The APR is 15.99% and the minimum payment each month is 4% of the balance. Determine the finance charge, new balance, and minimum payment required for the first month, and the starting balance for month 2 in the table below (*round to the nearest cent, do not include units with your answers)*:

Month | Carry-over balance | Finance charge | New balance | Minimum payment |

1 | $400 | —————— | ————— | ——————- |

2 | ——————- |

**Correct Answers**

**Answer 1: 5.33**

**Answer 2: 405.33**

**3rd Answer : 16.21**

**Answer 4: 389.12**

Lori buys a $890 certificate of deposit (CD) that earns 7% interest that compounds monthly. How much will the CD be worth in 9 years? (*Express your answer rounded correctly to the nearest cent. Do not include units on your answer.*)

**1,668.02** (margin of error +/- 0.1%) **–** **Correct**

In the rise of online shopping, malls are losing storefronts. The local mall started with 86 stores at the time that it was opened, but has consistently lost 6 stores per year for each year the mall has been open. Which of the following models represents the number of stores in the local mall at any given year, x?

86x – 6

**-6x + 86** **–** **Correct**

− 6 ( 86 )ᵡ

0.94x + 86

86 ( 0.94 )ᵡ

86 ( − 6 )ᵡ

Consider the graph below, then construct the appropriate model to represent the growth of the demogorgon population.

y = 300 (3) ^t

**Correct Answers**

**Answer 1:** **A**

**2nd Answer:** **1**

**Answer 3:** **(3)**

**Answer 4:** **^t**

The half-life of a radioactive substance is one day, meaning that every day half of the substance has decayed. Suppose you have 304 grams of this substance. Construct an exponential model for the amount of the substance remaining on a given day. Use your model to determine how much of the substance will be left after 4 days. (*Express your answer rounded correctly to the nearest tenth of a gram. Do not include units with your answer.*)

**19** (margin of error +/- 2%)** –** **Correct Answer**

A particular type of mold is growing 9.7% per hour. Assuming that mold growth continues at this rate and there were 14,000 spores at 12:00am, estimate the expected number of mold spores at 3:30am. (*Round your answer to the nearest whole spore. Do not include units on your answer.*)

**19,358 –** **Correct**

Use the graph below to calculate the growth factor on the savings account graphed. *Express your answer as a decimal rounded to the nearest thousandth.*

**1.005** (with margin: 1) **– Correct**