Three investments,X , Y and Z, are grouped into a single fund with weightings of 145, 156 and 99 respectively. Over a period of 4 years they increase in value, with each increase expressed as an index as shown in the following table:
Investment Index Weighting
A 154 145
B 145 156
C 130 99
(a) Calculate the composite (weighted) index for the three investments combined.
A second fund includes the same three investments, A, B and C, together with a fourth investment D.The weightings of investments A, B and C are as above, and the weighting of investment D is 50.Over the same period, the weighted index of the four investments combined is 141.6.
(b) Calculate the index representing the increase in value of investment D, over the four -year period.