问题
单项选择题
For an activity, the optimistic, most likely and pessimistic estimates are 12, 16 and 18 respectively. Which of the following statement is correct
A) There is 68.26% chance that the activity will be completed in 15 to 17 days.
B) There is 95.44% chance that the activity will be completed in 15 to 17 days.
C) There is 68.26% chance that the activity will be completed in 14.67 to 16.67 days.
D) There is 93.73% chance that the activity will be completed in 15 to 17 days.
答案
参考答案：C
解析： 某个活动，最乐观的估算是12；最可能估算是16；最悲观估算是18。下列哪个说法是正确的
A) 有68.26%的概率，活动将在15～17天之内完成。
B) 有95.44%的概率，活动将在15～17天之内完成。
C) 有68.26%的概率，活动将在14.67～16.67天之内完成。
D) 有93.73%的概率，活动将在15～17天之内完成。
该活动平均估算值是15.67；标准差是(18-12)/6=1；14.67到16.67之间正好左右各一个标准差。概率为68.26%。