The Economist: Numbers Guide summary

If you’re considering making an investment, you’ll be keen to work out how much your money will be worth in the future. You can calculate this by taking two factors into account: interest rates and inflation.

Interest is the price paid for the use of money, so the calculation of interest rates is crucial when comparing investment opportunities. 

Let’s look at three tools that, when combined, offer a highly effective way of describing any set of related numbers. To help put them into practice, start by considering the number of sales that a real estate company makes per day. 

First, you need a way to measure the average or “midpoint” value of a set of numbers. The most common way of measuring an average is by finding the mean, which is done by adding all the scores together and dividing the sum by the number of scores. 

In reports and presentations, tables and charts can be instrumental in conveying your message. They can bring order to your data, while still displaying all the original information. 

Tables tend to serve one of two main functions, which is presenting data or interpreting it.

Forecasting is all about predicting the future, especially future market trends, which is why it is a fundamental part of good decision-making in business. 

So, how is forecasting done? Let’s look at the three main approaches.

If you took a handful of wheat seeds out of a sack, you could consider your handful to be a sample, while the entire sack would represent the parent population. 

Samples are used to present statistical information across many disciplines, especially in business. Working with samples can be highly effective if you take the right approach. 

Many business contexts involve uncertainty or risk. Decision-making needs to be approached accordingly, but how exactly? 

Consider this example. King Burgers intends to open a new location. Should it open a large or small restaurant? The King family’s experience suggests that a big locale generates $500,000 in profit if popular, but incurs a $300,000 loss if not.

Forecasting trends, analyzing data and presenting your findings effectively are all made possible with a basic understanding of mathematical tools. These skills are simple yet powerful, and by mastering each one, you’ll be able to employ them with confidence to improve your decision-making abilities.