From the following fixed base number index (F.B.I.) prepare chain base indes (C.B.I.)

Question: From the following fixed base number index (F.B.I.) prepare chain base indes (C.B.I.)

Year: 1980 1981 1982 1983 1984 1985
(C.B.I.): 220 250 300 280 350 415

Solution:

Conversion from F.B.I. to C.B.I.

YearChain base indexConversionFixed index
1980220100.00
1981250(250×220)/100113.64
1982300(300×250)/100120.00
1983280(280×300)/10093.33
1984350(350×280)/100125.00
1985415(415×350)/100118.57