Portfolio beta calculationSecurity A: $2\mathrm{.}9$Security B: $1\mathrm{.}4$Security C: $0\mathrm{.}83$Investor X portfolio:INVESTOR'S PORTFOLIOSecurity A$-60\%$Security B$-30\%$Security C$-10\%$RESULT: $-(2\mathrm{.}9*60\%)+(1\mathrm{.}4*30\%)+(0\mathrm{.}83*10\%)=2\mathrm{.}243$Portfolio Beta for investor X is $2\mathrm{.}243$