For the given five values 15, 24, 18, 33, 45, which of the following is not the three years moving average?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 21
A three-year moving average is the mean of each set of three consecutive values. Five values give three such averages:
\( \displaystyle \frac{15+24+18}{3}=\frac{57}{3}=19 \)
\( \displaystyle \frac{24+18+33}{3}=\frac{75}{3}=25 \)
\( \displaystyle \frac{18+33+45}{3}=\frac{96}{3}=32 \)
The moving averages are 19, 25 and 32, so 21 is not one of them.