A. girl B. He C. His D. Her E. This F. friends
30,42,41,36,44,40,37,37,25,45,29,43,31,36,49,34,33,43,38,42,32,34,46,39,36.
根据上述数据得到样本的频率分布表如下:
分组
频数
频率
25,30
3
0.12
(30,35
5
0.20
(35,40
8
0.32
(40,45
n1
f1
(45,50
n2
f2
当我们因意外而无法履行对他人的承诺时,正确的做法是( )