Problem Solving

试题详情

题目:

The residents of Town X participated in a survey to determine the number of hours per week each resident spent watching television. The distribution of the results of the survey had a mean of 21 hours and a standard deviation of 6 hours. The number of hours that Pat, a resident of Town X, watched television last week was between 1 and 2 standard deviations below the mean. 
Which of the following could be the number of hours that Pat watched television last week?

选项:

A、30 
B、20 
C、18 
D、12 
E、6

答案:

D

提问:

请问老师这题解题思路,谢谢老师![img=/uploads/askimgs/gmat-20230606-102130.jpeg]
评分: 1
浏览: 1106

提问:

为什么选D呢?感觉题目的意思没理解清楚~
评分: 2
浏览: 1379
点我领取
免费专项课程
在线咨询