###### By Christina Elias

#### Chapter 5: Polls and Surveys

Polls and surveys are a common appearance in news articles, used often to add emphasis to a certain trend or topic. Before getting into it, here is the definition of each:

- “
**Polls**are an estimate of public opinion on a single topic or question. Polls are most frequently used in political circles and are based on representative samples of the population.” - “
**Surveys**are also based on representative samples of the population but usually include multiple questions and are used in a wide variety of social science settings.”

The source and methods of gaining the information are just as important as the results, as it adds credibility to the results and therefore the reporting. The confidence of researchers in their methods is important, as is the margin of error, which indicates the accuracy of results. It is based on the sample size because the more people sampled, the higher the confidence level and smaller the margin of error, and vice versa.

##### Chapter 6: Business

Business reporting is one of the areas in journalism that involves the most math. Numbers appear in the business in multiple different ways and are often released at regular intervals, which is why it’s so important reporters have a clear understanding of what they mean.

##### Formulas to know:

- gross margin = selling price – cost of goods sold
- This can be used to figure out how much a product has been marked up in order to make a profit after subtracting materials, production costs taxes, etc.

- gross
**profit**= gross margin x number of items sold **net**profit = gross margin – overhead (money spent on operating costs like payroll, rent, utilities, etc.)

#### Chapter 7: Stocks and Bonds

Stocks and bonds are common ways for businesses (and the government, when it comes to bonds) to raise cash. When someone buys a stock, they become a part-owner in that company, which makes it important for buyers to know how to navigate the world of stocks and bonds, which can be quite complicated.

##### Formulas to know:

- current yield = (interest rate x face value) ÷ price
- bond cost (interest) = amount x rate x years

#### Chapter 8: Property Taxes

According to Chapter 8, “Property taxes are the largest single source of income for local government, school districts and other municipal organizations.” Property taxes are extremely important to people in the community and in leadership positions, so it’s equally as important to understand how they work.

Property taxes are measured in **mills**, which amounts to 1/10 of a cent. A **mill levy**, then, demonstrates the property taxes collected in terms of one mill per dollar of the property’s assessed value.

##### Formulas to know:

- mill levy = taxes to be collected by the government body ÷ assessed valuation of all property in the taxing district
- assessed value of a property = appraisal value x rate
- tax owed = tax rate x (assessed value of the property ÷ $100)

#### Give it a go with practice problems

- Researchers polled 1,000 people and are 95 percent confident in their results, which means there is still a 3.1 percent margin of error. If 820 of those polled responded positively to the question, what is the confidence interval?
- A business makes a product for $7.86 each, then sells it for $13.50. What is the gross margin? If the business sells 300 that month, what in the gross profit?
- A state is selling 3-year bonds at $52,750 at a rate of 6 percent. How much will the bonds end up costing the state government?
- A house is appraised at $75,000 and has a tax rate of 40 percent its true value. What is the assessed value of the property?