Re: [商管] [統計]-幾題觀念題
※ 引述《ingles (transparent)》之銘言：
: 1. A recent article in the paper claims that business ethics are at an
: all—time low. Reporting on a recent sample, the paper claims that 41% of
: all employees believe their company president possesses low ethical
: standards.Suppose 20 of a company's employees are randomly and independently
: sampled and asked if they thought their company president had low ethical
: standards and their years of experience at the company.
: Could the probability distribution for the number of years of experience be
: modelled by binomial probability distribution?
: (A) No, the employees would not be considered independent in the present
: sample.
: (B) Yes, the sample size is n = 20.
: (C) No, a binomial distribution requires only two possible outcomes for each
: experimental unit sampled.
: (D) Yes, the sample is a random and independent sample.
我會選C 因為他實驗時問了1.想法和2.工作年資
不符合二項分配只有兩個出象的定義
A選項：題目告知隨機抽取 因此每次實驗應該是獨立
B : 若n是20 那p的值(年資比例)題目並沒有給 不構成二項
D ：隨機且獨立的條件 還無法構成二項
: 2.The registrar's office at State University would like to estimate the average
: commute time and determine a 95% confidence interval for the average commute
: time of evening university students from their usual starting point to campus.
: A member of the staff randomly chooses a parking lot and selects the first
: 100 evening students who park in the chosen lot starting at 5:00 p.m.
: The confidence interval is:
: (A) not meaningful because the sampling distribution of the sample mean is
: not normal.
: (B) meaningful because the sample size exceeds 30 and the central limit
: theorem ensures normailty of the sampling distribution of the sample mean
: (C) not meaningful because of the Tack of random. sampling.
: (D) meaningful because the sample is representative of the population.
我會選B
由於CLT 使得CI有意義
A:大樣本的抽樣分配 可逼近常態
C：也很像對 並無詳述如何隨機抽取 但題目有說"隨機"選了一個停車亭
D：樣本要代表母體 再附加一些條件較合適
: 麻煩板上強者提供你們的看法~謝謝囉^^
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