[商管] [統計] 期望值問題
問題 :
Three restaurants provide dinner for 100 students. They served, respectively
,20, 30 and 50 students. One of the students is randomly selected.
Let X denotes the number of students that have dinner at the same restaurant
with this randomly selected student.
求 E(X) ???
這題主要看不懂這個期望值是在問什麼
根據題意為，隨機變數 X 表示在同家餐廳吃飯的學生數
求E(X) ?
解答是寫
E(X) = 20 * 0.2 + 30 * 0.3 + 50 * 0.5 = 38
無法了解這38人是代表什麼的期望值 ??
還請版上版友幫忙解惑，小弟感激不盡 !!!
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