PP1-PS-110

[chiachen1223]

請大家幫忙解答一下！謝謝！

110. 11364-!-item-!-187;#058&007646 答案: D
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?

(A) 30
(B) 20
(C) 18
(D) 12
(E) 6

[ipas3]

這題PP詳解有我把它貼出來

題目的數據: 平均數(mean) :21 hrs 標準差(standard deviation) : 6 hrs
由Pat 上星期看電視的時間在1~2個標準差之下可得知(between 1 and 2 standard deviations below the mean)，時間範圍應該坐落在9hrs~15hrs之間
答案D 符合算出來的要求

(註) 也就是說 21-2*6 < Pat < 21-1*6


(jw1103.hsu@gmail.com 徵求有圖的PP1/PP2 math PS)