For the given five values, 15, 24, 18, 33, 42, the three-year moving averages are
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 19, 25, 31
A three-year moving average is the mean of each run of three consecutive values, moving one value at a time:
\( \displaystyle \frac{15 + 24 + 18}{3} = \frac{57}{3} = 19 \)
\( \displaystyle \frac{24 + 18 + 33}{3} = \frac{75}{3} = 25 \)
\( \displaystyle \frac{18 + 33 + 42}{3} = \frac{93}{3} = 31 \)
So the moving averages are 19, 25, 31.