Labels and scope
Check the title, axes, units, period and sample definition. A table of revenue in thousands needs a different calculation from a table of customers. Check whether percentages share the same denominator. The data may exclude a region or cover only one part of the business.
Growth and percentage points
Growth from $900,000 to $1 million is $100,000 divided by $900,000, or about 11.1%. A rate falling from 2% to 1.5% declines by 0.5 percentage points. Its relative reduction is 25%. State which measure you calculated so the listener can interpret the answer.
Weighted averages
If 200 units sell for $40 and 300 units sell for $60, the average selling price is total revenue divided by 500 units. The result is $52. A simple average of the two prices gives $50 and ignores the greater volume sold at the higher price. Choose a weight that matches the quantity being averaged.
A pattern needs an explanation
An exhibit may show that a route lost passengers while ticket prices fell. It does not establish why either change occurred. Demand, competitors and a change in passenger mix could be worth investigating. Describe the observed relationship, then request evidence that would distinguish your explanations.
The effect on the decision
Explain how your calculation relates to the decision. A channel with fewer visitors may still generate more completed orders if its conversion rate is higher. Comparing completed orders can change where you investigate next. Before recommending a budget shift, identify the information still missing, such as acquisition cost.
Use the right units and denominator for your comparison, then explain how the result affects the decision.