For the values 22, 25, 28, 31, 40, 43, the three yearly moving averages are
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 25, 28, 33, 38
A three-yearly moving average is the mean of each set of 3 consecutive values; six values give four averages:
\( \displaystyle \frac{22+25+28}{3}=25 \)
\( \displaystyle \frac{25+28+31}{3}=28 \)
\( \displaystyle \frac{28+31+40}{3}=33 \)
\( \displaystyle \frac{31+40+43}{3}=38 \)
So the moving averages are 25, 28, 33, 38.