987667 - 経済統計練習帳

var a = new Array();
var b = new Array();
 
function sample(){
 
n = 5;
p = 0.2;
q = 0.8;
 
a[0] = 1;
a[1] = n;
for (s = 2; s < n + 1;s++ ){
a[s]=a[s-1]*(n-s+1);    
}
 
 
b[0] = 1;
    b[1] = 1;
    for (s = 2; s < n + 1;s++ ){
    b[s]=b[s-1]*s;    
    }
 
 
    p2=0;
    for (r = 0; r < 6;r++ ){
 
        p1 = 1;
    for (s = 1; s < r + 1;s++ ){
    p1=p1*p;    
    }
 
    for (s = 1; s < n-r + 1;s++ ){
    p1=p1*q;    
    }
 
 
    p2 =p2+ r*a[r] * p1 / b[r];
 
} 
 
        $("#memo").html(p2);
 
 
 
}