Page 30 - TOP CLASS MATHS T5 KSSM

Mathematics Form 5 Chapter 7 Measures of Dispersion for Grouped Data

(c) 7 + 3
(d) Percentage / Peratusan = × 100%
60
Frequency = 16.67%
Kekerapan

16

14

12
10

8

6

4

2
0
75.5 85.5 95.5 105.5 115.5 125.5 135.5 145.5
Monthly pocket money (RM)/ Wang saku bulanan (RM)

HOTS Challenge

The following frequency distribution table shows the age, in years, of a group of visitors to a theme park. HOTS Analysing
Jadual taburan kekerapan berikut menunjukkan umur, dalam tahun, sekumpulan pelawat yang mengunjungi suatu taman tema.
Age (years) / Umur (tahun) 5 – 9 10 – 14 15 – 19 20 – 24 25 – 29 30 – 34 35 – 39
Frequency / Kekerapan 11 19 27 m 14 9 2

2
If the variance of the above data is 58.5 year , calculate the value of m.
Jika varians bagi data di atas ialah 58.5 tahun , hitung nilai m.
2
Answer / Jawapan:
Variance / Varians = 58.5 Age (years)
Σfx 2 Σfx 2 f x fx fx 2
–   = 58.5 Umur (tahun)
Σf Σf
484m + 33 238 22m + 1 504 2 5 – 9 11 7 77 539
–   = 58.5 10 – 14 19 12 228 2 736
m + 82 m + 82
(22m + 1 504) 2 484m + 33 238 15 – 19 27 17 459 7 803
= – 58.5
(m + 82) 2 m + 82 20 – 24 m 22 22m 484m
(22m + 1 504) 2 484m + 33 238 – 58.5(m + 82)
= 25 – 29 14 27 378 10 206
(m + 82) 2 m + 82 30 – 34 9 32 288 9 216
(22m + 1 504) 2
= 28 441 + 425.5m 35 – 39 2 37 74 2 738
m + 82
2
(22m + 1 504) = (28 441 + 425.5m)(m + 82) Σf = m + 82
484m + 66 176m + 2 262 016 = 425.5m + 63 332m + 2 332 162 Σfx = 22m + 1 504
2
2
58.5m + 2 844m – 70 146 = 0 Σfx = 484m + 33 238
2
2
2
× 10: 585m + 28 440m – 701 460 = 0
÷ 45: 13m + 632m – 15 588 = 0
2
(13m + 866)(m –18) = 0
866
m = – (Rejected / Ditolak), m = 18
13
Hence / Maka, m = 18
Quiz 7
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