plumiConfidence intervals: WJEC A‑Level Further Maths questions
Every WJEC A-Level Further Maths exam question on 5.4 Confidence intervals, 2018–2025, with its mark scheme and examiner’s report.
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All 10 questions on Confidence intervals, as a list
- Summer 2025, Unit 5, Q1 (9 marks): 1. A manufacturer produces light bulbs and claims that the average lifespan of these bulbs is 800 hours with a standard deviation of 50 hours. A sample of 100 b
- Summer 2025, Unit 5, Q6 (11 marks): 6. An anthropologist selects a random sample of 12 women from The Netherlands and records their heights, in cm, as follows. 164 175 177 173 174 174 178 167 171
- Summer 2024, Unit 5, Q1 (9 marks): 1. During practice sessions, a basketball coach makes his players run several ‘line drills’. (a) He records the times taken, in seconds, by one of his players t
- Summer 2024, Unit 5, Q3 (7 marks): 3. Tony runs a pie stand that sells two types of pie outside a football ground. He wants to estimate the probability that a customer will buy a steak pie rather
- Summer 2023, Unit 5, Q3 (11 marks): 3. Athletes who compete in the 400 m event have resting heart rates (RHR), measured in beats per minute, which are normally distributed with known standard devi
- Summer 2023, Unit 5, Q7 (7 marks): 7. Branwen intends to buy a new bike, either a Cannotrek or a Bianchondale. If there is evidence that the difference in the mean times on the two bikes over a 1
- Summer 2022, Unit 5, Q1 (5 marks): 1. Rachel records the times taken, in minutes, to cycle into town from her house on a random sample of 10 days. Her results are shown below. 15·5 14·9 16·2 17·3
- Summer 2022, Unit 5, Q4 (12 marks): 4. The Department of Health recommends that adults aged 18 to 65 should take part in at least 150 minutes of aerobic exercise per week. The results of a survey
- Summer 2019, Unit 5, Q1 (8 marks): 1. A coffee shop produces biscuits to sell. The masses, in grams, of the biscuits follow a normal distribution with mean µ. Eight biscuits are chosen at random
- Summer 2019, Unit 5, Q4 (11 marks): 4. Rugby players sometimes use protein powder to aid muscle increase. The monthly weight gains of rugby players taking protein powder may be modelled by a norma
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