The given series is in the below pattern,
First term = 16
Second term = First term × 0.25
⇒ Second term = 16 × 0.25 = 4
Third term = Second term × 0.50
⇒ Third term = 4 × 0.50 = 2
Fourth term = Third term × 0.75
⇒ Fourth term = 2 × 0.75 = 1.5
Fifth term = Fourth term × 1
⇒ Fifth term = 1.5 × 1 = 1.5 ;
∴ ? = 1.5
Similarly , we can find all others terms also.
Sixth term = Fifth term × 1.25
⇒ Sixth term = 1.5 × 1.25 = 1.875
Hence , Fourth term = 3
