# Pictogram questions about statistics

This figure shows a graph taken from an advertisement for an investment that promises to pay a higher interest rate than bank accounts and other competing investments is this graph a correct comparison of the four interest rates? Explain your answer.

My answer for this question is "No, this graph is not a correct comparison of four interest rates because it is missing l=ables and legends tell what variables are plotted." But I am not quite sure if my answer is correct. Anyone can help me?

• That IS a strange question! You could say that the triangle-like areas are scaled in two dimensions thus making the area grow as a square of the factor of increase in height. So the areas grow more than the figures $3.5\%,4.4\%,5.1\%$ and $5.9\%$ as the areas will have relative sizes $3.5:5.5:7.4:9.9$. – String Oct 16 '14 at 8:26

So $5.9\%$ is almost $1.7$ times $3.5\%$ and this is shown by the heights of the cones.
But the cone on the right is also substantially wider than the one on the left, so the visual area is much more than $1.7$ times (if it was $1.7$ times the width then the area on the right would be more than $2.8$ that on the left). If your brain interprets the pictures as volumes, you may also see a further factor of $1.7$ front to back, creating an even more disproportionate impression.