Page 29 - TOP CLASS MATHS T5 KSSM

Mathematics Form 5 Chapter 7 Measures of Dispersion for Grouped Data
(c) (b) Calculate the standard deviation of the data.
Hitung sisihan piawai bagi data itu.
Frequency
Kekerapan (c) Draw a frequency polygon for the data, using the scale
of 2 cm to RM10 on the horizontal axis and 2 cm to 2
pupils on the vertical axis.
10
Lukis satu poligon kekerapan bagi data tersebut dengan
menggunakan skala 2 cm kapada RM10 pada paksi
9
mengufuk dan 2 cm kepada 2 orang murid pada paksi
mencancang.
8
(d) Based on the frequency polygon in (c), find the
percentage of pupils who received a monthly pocket
7
money of more than RM120.
Berdasarkan poligon kekerapan di (c), cari peratusan murid
6
yang menerima wang saku bulanan melebihi RM120.
5 Answer / Jawapan:
(a) (i)
4
Pocket money (RM) Frequency Midpoint
Wang saku (RM) Kekerapan Titik tengah
3
71 – 80 0 75.5
2 81 – 90 6 85.5
91 – 100 13 95.5
1
101 – 110 16 105.5
0 111 – 120 15 115.5
43 48 53 58 63 68 73 78
Savings (RM)/ Simpanan (RM) 121 – 130 7 125.5

(d) Number of pupils = 10 + 8 + 4 131 – 140 3 135.5
Bilangan murid
= 22 141 – 150 0 145.5
(ii) From the ogive, / Daripada ogif,
5. The diagram is an ogive showing the monthly pocket Q 1 = 98.0
money, in RM, of a group of 60 pupils. Q 3 = 117.0
Rajah di bawah ialah satu ogif yang menunjukkan wang saku Interquartile range / Julat antara kuartil
bulanan, dalam RM, bagi sekumpulan 60 orang murid. = 117.0 – 98.0
= RM19
Cumulative frequency
th
Kekerapan longgokan (iii) 55 percentile / Persentil ke-55
= RM109
60
(b)
50
Pocket money
Wang saku f x fx fx 2
40
(RM)
30 81 – 90 6 85.5 513 43 861.5
91 – 100 13 95.5 1 241.5 118 563.25
20
101 – 110 16 105.5 1 688 178 084
10 111 – 120 15 115.5 1 732.5 200 103.75
121 – 130 7 125.5 878.5 110 251.75
0
80.5 90.5 100.5 110.5 120.5 130.5 140.5 150.5 131 – 140 3 135.5 406.5 55 080.75
Monthly pocket money (RM)/ Wang saku bulanan (RM)
2
Σf = 60, Σfx = 6 460, Σfx = 705 945
(a) Based on the ogive, 705 945 6 460 2


–
Berdasarkan ogif itu, σ = 
60
60
(i) complete the table in the answer space, = RM13.177
lengkapkan jadual di ruang jawapan,
(ii) determine the interquartile range,
tentukan julat antara kuartil,
th
(iii) determine the 55 percentile.
tentukan persentil ke-55.
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