AnSWErS to tHE StudEnt'S Book ExErCiSES - Hodder Plus Home

4 a)Mark50403020100400 500 600Circumference of head (mm)b) No correlation c) Nod) Don’t know the ages of the people involved.Mixed exercise 39 (page 531)1 a)Time 0 < t , 5 5 < t , 10 10 < t , 15 15 < t , 20(t mins)Frequency 6 7 5 2b)2 a)Frequencyy86420 5 10 15 20xTime (minutes)c) 5 < t , 10 d) 5 < t , 10Frequency2015105y0304050 60 70 80 90Marksb) Suitable comments include the following.The marks range from 30 to 90.There are few low and high marks.Most of the marks are around 50 to 60.c) 50 < m , 60 d) 70 e)2_73 a), c)18001600140012001000800600400200Average weight (g)01 2 3 4 5 6 7 8 9Age of rabbit (months)b) Strong positive correlationd) (i) About 800 g (ii) About 1700 ge) No. A rabbit’s weight cannot keep increasing.xChapter 40Exercise 40.1 (page 536)1 a) (i) 3 (ii) 3 (iii) 5 (iv) 3.456b) (i) 50 (ii) 50 (iii) 5 (iv) 49.632c) (i) 1 (ii) 1 (iii) 5 (iv) 1.443d) (i) 2 (ii) 2 (iii) 4 (iv) 1.7282 a) 1.96 b) 1.04 c) 2.987 d) 4.4563 a) 4.51 b) 27.04 c) 12.75 d) 3.16254 £1.07 5 7.52Exercise 40.2 (page 542)1 a) (i) 50 (ii) 13.6b) (i) 20 (ii) 7.22c) (i) 40 (ii) 14.1d) (i) 20 (ii) 6.552 a) (i) 0–4 (ii) 20 (iii) 6.98b) (i) 0–9 (ii) 40 (iii) 15.5c) (i) 250–299 (ii) 250 (iii) 164.7d) (i) 30–44 (ii) 45 (iii) 31.53 a) (i) 3–5 (ii) 3.62b) (i) 4–7 (ii) 7.3c) (i) 30–39 (ii) 32.25d) (i) 75–99 (ii) 754 30.3 5 179.5Exercise 40.3 (page 546)1 a) (i) 50 cm (ii) 31.46 cmb) (i) 40 g (ii) 25.11 gc) (i) 16 cm (ii) 68.56 cmd) (i) 50 mm (ii) 16.04 mm2 a) (i) 0 < x , 3 (ii) 9.85 daysb) (i) 120 < x , 130 (ii) 121.36 gc) (i) 22 < x , 26 (ii) 21.2 cmd) (i) 50 < x , 55 (ii) 54.83 miniutes3 a) 250 < x , 300b) 250 < x , 300c) £270.004 18.3 g 5 165.71 penceMixed exercise 40 (page 548)1 a) (i) 6 (ii) 7 (iii) 4.488b) (i) 50 (ii) 7 (iii) 50.27c) (i) 1 (ii) 6 (iii) 1.42d) (i) 6 (ii) 5 (iii) 6.36e) (i) 2 (ii) 5 (iii) 3.47f) (i) 18 (ii) 5 (iii) 17.542 £11.363 2.71 (2 d.p.)4 a) (i) 20 cm (ii) 22.09 cmb) (i) 100 km/h (ii) 30.11 km/hc) (i) 50 seconds (ii) 59.33 secondsd) (i) 25 kg (ii) 55.8 kg5 a) 10 < x , 20 b) 10 < x , 20c) 19.31 minutes6 £24 888.89 (or £24.89 thousand)Higher WJEC GCSE Mathematics © 2010, Hodder EducationAnswers to the Student’s Book exercises 237