For the given five values 12, 16, 20, 30, k, the three years moving averages are 16, 22, 28, then the value of k is :

34

The correct answer is Option (4) → 34

First moving average,

$\frac{12+16+20}{3}=16$

$\frac{48}{3}=16$

$16=16$

Second moving average,

$\frac{16+20+30}{3}=32$

$\frac{66}{3}=12$

Third moving average,

$\frac{20+30+k}{3}=28$

$k=34$