Re: [計量] 兩題問題 麻煩各位了
※ 引述《psps1225 (鯛魚燒)》之銘言：
: 標題: [計量] 兩題問題 麻煩各為了
: 時間: Sun Sep 22 09:42:45 2013
:
: 1. What is the nonnegative difference between the values of 3(k-2) and 3k-6?
:
: a.0
: b.2
: c.4
: d.6
: e.It cannot be determined from the information given.
3k-6 = 3(k-2) 提出公因數
後項等於前項
: 2.WINK, Inc. is made up of 450 employees who work a total of 13500 hours per
:
: week. If the number of weekly work hours per person has a normal distribution
:
: and the standard deviation equals 7 hours, how many employees work more than
:
: 37 hours per week?
Sum = 13500
Avg. = 13500/450 = 30
37剛好位於+1σ
normal distribution
-3σ -2σ -σ Avg. σ +2σ +3σ
| 2% | 14% | 34% | 34% | 14% | 2% |
30 37
超過的比例是14%+2%
450 x 16% = 72
: (P.S.標準差問題一直是我的弱項 可能跟高中數學沒怎麼接觸有關
: 大學時實驗數據整理也是抄公式 按按計算機就解決了... 順便也求個速成法吧XD)
:
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