In $1995$,
Investment in Electricity in Chittoor= $815.2$ Rs.
Investment in Electricity in Khammam= $2065.8$ Rs.
Investment in Thermal Energy in Chittoor= $690.4$ Rs.
Investment in Thermal Energy in Khammam= $1232.7$ Rs.
∴ Total investment in Electricity & Thermal Energy in $1995$ = $815.2 + 2065.8 + 690.4 + 1232.7 = 4804.1$ Rs.
∴ Total investment in Electricity & Thermal Energy in $1995$ are of a total of $\left [ \dfrac{4804.1}{2981.1+7081.6}\% \right ] = 47.74\% $ of the total investment made in these two districts (Chittoor & Khammam) in $1995$.