For given five values 1.5, 1.8, 1.9, 2.2, 2.6, the average of three years moving average is :

1.98

The correct answer is Option (2) → 1.98

The three year moving average is,

$MA=\frac{\text{Sum of 3 consecutive values}}{3}$

for $(1.5,1.8,1.9)$:

$\frac{1.5+1.8+1.9}{3}=1.7333$

for $(1.8,1.9,2.2)$:

$\frac{1.8+1.9+2.2}{3}=1.9667$

for $(1.9,2.2,2.6)$:

$\frac{1.9+2.2+2.6}{3}=2.2333$

final average = $\frac{1.7333+1.9667+2.2333}{3}=1.98$