i'm question about Gussian Random number generation. Page 5 in the book there is an Algorithm about Gussian random number generation, which is as follows:

double GetOneGussianBySummation(){

double result=0.0;

for(unsigned long j=0;j<12;j++)

result+=rand()/static_cast<double>(RAND_MAX);

result-=6.0;

return result;

}

can i understand above code in this way:

aasume that x=rand()/static_cast<double>(RAND_MAX); i can induce that x is a uniformly variable.further more,i can get Expection(result)=Exp(x00+...+x11-6)

=Exp(x00)+...+Exp(x11)-6=12Exp(x)-6=12*1/2-6=0 and Variance(result)=Var(x00+...+x11-6)=12Var(x)=12*1/12=1. as a result ,i can see varaible result's Exp and Var are 0 and 1 respectively.but according to function name GetOneGussianBySummation ,does that mean that result is a normal Variable?but i only konw its exp and var,i cant prove variable is a normal variable.

would y like to spare some time to explain it ?thanks a million.