Math - Percentages?

2020-10-25 9:37 pm
The price of a mobile phone is $8450 in 2019. If it depreciates at a constant rate of 3% per year, find the decrease in its price from 2017 to 2021. (Correct your answer to 3 significant figures.)

Thank you very much!
更新1:

如何計算出2017年價錢是8964.605?

回答 (2)

2020-10-26 9:55 am
2017 至 2021 總跌幅是 11.5%
公式:    1 - (1-年跌率)^4

2017 價格是
    $8450 ÷ (0.97)^2 = $8980.76


因為會被隱藏, 現在又沒意見區可放, 只能簡回如上.

2017 價格 "8964.605" 是用不正確, 或可算是近似算法計算的,
具體算式是
    2019價格 × (1 + 年跌率)^2
正確算法是
    2019價格 ÷ (1 - 年跌率)^2
2020-10-25 10:16 pm
2017年價錢是8964.605,2021年價錢是7950.605,總跌幅是1014


收錄日期: 2021-04-24 08:02:44
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20201025133743AA0e7GN

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