A.scanf("%d",p1[3])
B.scanf("%d",arr[3])
C.scanf("%d",p1)
D.scanf("%d",p1+3)
A.int a[3][4]={0};
B.int a[3][4]={{1,2},{1,2,3},{1,2,3,4}};
C.int a[3][]={0,1,2,3,4,5,6,7,8,9,10,11,12};
D.int a[][4]={1,2,3,4,5,6,7,8,9,10,11,12};
已知样本均值=5,求参数p的置信水平为95%的置信区间。