The first four chapters of Math Tools for Journalists details some of the important, basic facts that all journalists should know. These topics include the language of numbers, percentages, statistics and federal statistics.
All of these are important for journalists, as they can better convey and drive home important point for the readers.
In the first chapter, the language of numbers, it discusses the importance of conveying information through numbers and the appropriate use of numbers in text.
In the second chapter, percentages, the common uses for percentages in writing are discussed—percentage increase, percentage decrease, percentage of the whole and percentage points.
The third chapter, statistics, gives a basic understanding of statistics and the role manipulation of numbers plays for a journalist. This chapter talks about how statistics can be used to drive home the most salient and important points in text.
The final chapter, federal statistics, talks about unemployment rate, the CPI and GDP figures, and how to better understand them.
Chapter 2: Percentages in depth
The percentages chapter is especially important, as percentages can convey so many different ideas, and almost anything dealing with numbers in journalism can be manipulated into a statistic.
With percentages, as stated before, there are four main statistics that can be used to convey important ideas for the journalist. The first type is percentage increase/decrease. These are used to show change over time. The formula is conveyed as the following:
- Percentage increase/decrease = (new figure – old figure) / old figure
- Convert to a percentage by moving the decimal two places to the right.
One real-world application for percentage increase/decrease is in salary change, with stories about workers with change in salary. To put this number as a percentage can give it drastic implications (15 percent increase, 30 percent decrease, etc.)
Percentage of a whole is the next type of statistic that can be sought from percentages. This can be conveyed through the following formula:
- Percentage of a whole = subgroup / whole group.
- Move the decimal point two points to the right.
This type of statistic lends itself well when there is something that is part of a whole, but often is a large portion of the whole, such as a football team’s budget in an entire collegiate athletic budget.
The third type of statistic that can be derived from percentages is percentage points. There difference between percent and percentage points. Percents is out of one hundred, while percentage points are based out of the whole, not necessarily out of 100 percent.
Other things that were emphasized in this chapter is both simple and annual interest, which can be derived from the following formula:
Interest = principal x rate (as a decimal) x time (in years)
Compounding interest is a term that accumulates over time, with more and more money being added to the interest as time goes on. Interest can be compounded monthly, annually, etc. The more often it is compounded, the quicker the interest will accumulate.
Example:
In Ohio, the May unemployment rate was 8.2%. In September, it was 14.5%. By how much percentage points did the unemployment rate grow from May to September?
Answer: 14.5%-8.2%=6.3%.
6.3%/8.2%= 76%. The unemployment rate climbed by 76 % from may to September.
Leave a comment