Data Interpretation
🔒 Log in to trackmedium importance~2 Q in Tier 116 formulas⚡ 10 shortcuts5 subtopics
Every formula in this topic, grouped by subtopic. Print it and pin it above your desk.
Reading tables: totals, differences, ratios
Total of a row/column
\text{total}=x_1+x_2+\cdots+x_k
Difference
\text{difference}=|A-B|
Ratio of cells
\text{ratio}=\frac{x_{ij}}{x_{kl}}\ \text{(simplify the fraction)}
Percentage change and comparisons
Percentage change
\Delta\%=\frac{\text{new}-\text{old}}{\text{old}}\times100
Share of total
\text{share}=\frac{\text{part}}{\text{whole}}\times100\%
Percentage points
\text{pp difference}=\Delta\%_1-\Delta\%_2
Pie charts: degrees, shares and totals
Angle to value
\text{value}=\frac{\theta}{360^\circ}\times\text{total}
Percent to angle
\theta=\text{share}\times3.6^\circ\ \text{per percent}
Share from angle
\text{share}=\frac{\theta}{3.6^\circ}\%
Averages from data
Average of cells
\bar{x}=\frac{\text{sum of cells}}{\text{number of cells}}
Weighted average
\bar{x}=\frac{n_1\bar{x}_1+n_2\bar{x}_2}{n_1+n_2}
Per-period value
\text{per period}=\frac{\text{total}}{\text{number of periods}}
Growth rates and successive changes
Growth rate
g=\frac{\text{new}-\text{old}}{\text{old}}\times100
Successive change
\text{factor}=\left(1+\frac{a}{100}\right)\left(1+\frac{b}{100}\right)
Reverse growth
\text{initial}=\frac{\text{final}}{\text{factor}}
Profit percent from table
\text{profit}\%=\frac{\text{income}-\text{expenditure}}{\text{expenditure}}\times100