Figure below shows the histogram of the I.Q. distribution of a group of children.
https://www.flickr.com/photos/130230543@N06/16176310902/in/photostream
(a) How many children are there in the group?
(b) Find the percentage of children whose I.Q. are 100 or higher.
(c) Public servant CY points out that 125 is the highest IQ in the group of children.
Do you agree? Why?
Figure below shows a pile of beads, which is in the shape of a right circular cone of base radius 15 cm and height 20 cm. The beads are in a cylindrical vessel of base radius 15 cm and height 20 cm.
https://www.flickr.com/photos/130230543@N06/15991269067/in/photostream
(a) By considering the volume of a cone, estimate the total volume of the beads and express your
answer in terms of π .
(b) Given that 3500 π cm3 of water is needed to fill up the cylindrical vessel, find
(i) the actual total volume of the beads in terms of π:,
(ii) the percentage error of the estimated total volume of the beads in (a).
Histogram, Approx & Error
2015-01-03 11:14 am
回答 (3)
2015-01-10 5:52 pm
✔ 最佳答案
IQ range ..... No. of children 70 - 80 ............. 3 80 - 90 ............. 8 90 - 100 ......... 14100 - 110 .......... 4110 - 120 .......... 6120 - 130 .......... 1(a) Number of children in the group :3＋8＋14＋4＋6＋1＝36
(b) Percentage of children whose I.Q. are 100 or higher :(4＋6＋1)/36 * 100%＝31.6% (corr. to 3 sf)
(c) I don't agree, as the highest IQ student is fall into the range 120 to 130,
so his/her highest IQ may be 129, not 125.
(a) Volume of cone＝(1/3) r² h πSo, estimate total volume of the beads is :(1/3) (15)² (20) π＝1500 π (cm³)
(bi) The actual total volume＝capacity of vessel－volume of water＝(15)² (20) π－3500 π＝1000 π (cm³)
(bii) percentage error＝(estimated－actual)/(actual) * 100%＝(1500 π－1000 π)/(1000 π) * 100%＝50%
2015-01-10 09:53:45 補充：
You are right, 130 will be grouped into 135 group.
2015-01-10 10:49 am
3+8+14+4+6+1
=35
4+6+1
=11
Yes, because 125 is the largest value of I.Q. in the data.
20*15^2π/3
=1500πcm^2
15^2π*20-3500 π
=1000πcm^2
(1500π-1000π)/1000π*100%
=50%
Tell me if there are any differences between your answer and my answer
Because I'm afraid that I may make some careless mistake or remember the rquations wrongly
And I'm not sure whether I'm answering 1(c) right
=35
4+6+1
=11
Yes, because 125 is the largest value of I.Q. in the data.
20*15^2π/3
=1500πcm^2
15^2π*20-3500 π
=1000πcm^2
(1500π-1000π)/1000π*100%
=50%
Tell me if there are any differences between your answer and my answer
Because I'm afraid that I may make some careless mistake or remember the rquations wrongly
And I'm not sure whether I'm answering 1(c) right
2015-01-03 12:46 pm
ALEX 你有沒試下做, 以你的程度應該識晒
收錄日期: 2021-04-15 17:46:43
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