1. Ricky got 67 ,59, 90 and 88 marks respectively in the tests . Find the marks in the final test so that the mean mark of the five tests will be 79.
2. If the mean of three numbers is 13 and the mean of another five numbers is 19 , find the mean of the eight numbers .
3. Given a set of data : 16 ,23 ,19 ,27 ,20
(a) Find its mean
(b) A datum is added to the given set of data and the mean is then increased by 50%. Find that datum.
Maths
2008-08-07 5:41 pm
回答 (1)
2008-08-07 6:05 pm
✔ 最佳答案
1. 79×5–(67 59 90 88)=712. (13×3 19×5)÷8 = 16.75
3.a.(16 23 19 27 20)÷5 = 21
3.b.(21×(1 50%))×6–(16 23 19 27 20)=94
參考: me
收錄日期: 2021-04-24 08:32:22
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