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

Chapter 41Exercise 41.1 (page 552)1 0.9 23 0.15 45 0.57 6Exercise 41.2 (page 553)1 0.7 23 0.35 45 0.11 6Exercise 41.3 (page 556)5_6__ 310__ 1749__ 620 5 __ 310__ 411__ 1201 4 2 123 17 4 £3005 a) 50b) 1506 50 yellow, 75 blue, 125 greenExercise 41.4 (page 557)1 a) Score 1 2 3 4 5 6Relativefrequency0.14 0.09 0.17 0.22 0.11 0.27b)1_ or 0.17 (to 2 d.p.)6c) Yes, the dice is biased. The relative frequencyfor 2 seems too low and the relativefrequencies for 4 and 6 seem too high.2 Small number of trials. Cannot be predicted fromthese past events.3 a) Party RelativefrequencyLabour 0.3Conservative 0.47Lib. Dem. 0.17Other 0.06b) 0.3104 a) __ 5 0.5 which is the probability of tossing a20coin and getting a head.102b) ___ 5 0.34 which is very different from 0.5.300c) Emma. More trials give a more reliableindication.5 a) Score 1 2 3 4Relative frequency 0.27 0.23 0.26 0.24b) Yes. All values are approximately equal to0.25.c) Either 225, 225, 225, 225 (if the spinner isfair) orScore 1 2 3 4Relative frequency 240 204 237 2196 a) 200 is a large number of trials.b) Travel by … Bus Car Bike WalkEstimate ofprobability0.245 0.24 0.115 0.4Mixed exercise 41 (page 559)17_92 0.353 0.1374 a) __b) 5 red, 8 white, 7 blue205 12 days106 a) __20 5 1_ , which is the probability of getting2heads with a fair coin.b) She is not necessarily correct. She shouldcarry out more trials.7 a) About 6739b) (i) ___400 (ii) ___ 279(iii) ___ 121400 400Chapter 42Exercise 42.1 (page 564)151 a) __23 b) __ 18232 a) 0.85 b) 0.653 a) 0.53 b) 0.168 c) 0.412d) 0.83 e) 0.564 The events are not mutually exclusive: 3_ 5 2 . 1.51_416 ___1257 a) 0.12 b) 0.4218 a) ___121 b) ___ 9121 c) ___ 1612119 a) __16 b) __ 916 c) __ 616 5 3_810 a) 0.216 b) 0.064 c) 0.432238Answers to the Student’s Book exercisesHigher WJEC GCSE Mathematics © 2010, Hodder Education