統計學題目求解

You are interested in purchasing a new car. One of the many points you wish to consider is the resale value of the car after 5 years. Since you are particularly interested in a certain foreign sedan

you decide to estimate the resale value of this car with a 95% confidence interval. You manage to obtain data on 17 recently resold 5-year-old foreign sedans of the same model. These 17 cars were resold at n average price of $12

700 with a standard deviation of $700. Create a 95% confidence interval for the true mean resale value of a 5-year-old car of that model.看不懂QAQ 懇求高手賜與解答(要有算式)
我先翻譯一下題目:你有興趣要買一台新車。

其中你想要考量的一點

是那台車子五年以後轉手的價格。

由於你對於外國的轎車特別感興趣

因此你決定要去估計轉手賣車之價格的95%信賴區間。

你得到的資料是17台車的五年後轉手價格之樣本模型。

這17輛車平均轉手售價是12700(美)元、標準差為700(美)元。

求出這個模型的5年後平均售價之95%信賴區間。

上面文章用原文且用$

所以推估是(美)元。

【解題】其實題目翻譯之後

這個題目也沒什麼大不了XD~~~本題的標準誤為S/√n=700/√17=169.7749....

取169.775。

因此平均數之95%(α=0.05)信賴區間為:μ±t(0.05

雙尾

n-1)*(標準誤)=12700±t(0.05

雙尾

16)*(169.775)=12700±(2.120)*(169.775)=12700±(359.923)=(12700-359.923

12700 359.923)=(12340.077

13059.923)。

如果哪裡有問題

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