The daily earnings of a taxi driver are normally distributed with a mean $500 and a standard deviation of $50.(a) What is the probability that the earnings on a particular day will be over $600?
(b) What is the probability that the earnings on a particular day will be between $420 and $530?
(c) Above what values will 90% of the daily earnings be expected to lie?
請這題數點計嫁?
2011-10-31 12:26 am
回答 (2)
2011-10-31 5:32 am
✔ 最佳答案
(a) P(X > 600)= P(Z > 2)
= 0.0228
(b) P(420 < X < 530)
= P(-1.6 < X < 0.6)
= 0.7257 - 0.0548
= 0.6709
(c) P(Z > -1.28 ) = 0.9
So, X = 500 + 50 * (-1.28) = 436
90% of the daily earnings will be greater than $ 436
2011-11-02 12:58 am
(C)part似計錯咗，麻煩計過佢。
收錄日期: 2021-04-26 14:55:55
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