Advanced Topics
In a nutshell: Basic math skills are crucial for solving IR questions efficiently and accurately.
## Essential Math for IR
The IR section blends logic with quantitative skills. While advanced math isn't required, comfort with basic arithmetic, percentages, ratios, and interpreting statistics is key.
## What to Know
- Percentages: Converting between fractions, decimals, and percents
- Ratios and Proportions: Comparing quantities and scaling values
- Averages and Medians: Summarizing data accurately
- Reading Data: Extracting precise values from tables and charts
## Handy Formulae
- Percentage Change: \( \frac{\text{New} - \text{Old}}{\text{Old}} \times 100\% \)
- Average: \( \frac{\text{Sum of Items}}{\text{Number of Items}} \)
## Tips
- Estimate when possible to save time.
- Don't get bogged down in calculations—focus on what the question is really asking.
Examples
- Calculating the average growth rate from a table of yearly sales.
- Using ratios to compare market shares in a bar chart.