Hint
Use the stated units and precision. Distinguish labels, integer counts and continuous measurements.
Worked solution
(a)
Distinguish labels, integer counts and continuous measurements.
Measured journey duration is continuous numerical.
Answer: continuous numerical
(b)
Sum each category count once.
Add the two nonoverlapping counts to obtain 16.
Answer: \(16\)
(c)
Distinguish excluded records from retained observations.
Subtract excluded measurements: \(\displaystyle 60-12=48\).
Answer: \(48\)
Maths4U indicative marking guidance
Maths4U indicative marking guidance, not an official mark scheme. Credit complete valid alternative methods and consequential reasoning. An unexplained result does not earn a method mark.
(a) · 2 marks
- 1 mark: Distinguish labels, integer counts and continuous measurements.
- 1 mark: Give the correct requested result, retaining signs, units and any domain restrictions.
Alternative methods: Any complete mathematically valid alternative method with the same restrictions and equivalent exact result is acceptable.
Common error: Keep intermediate values exact until the final step.
(b) · 2 marks
- 1 mark: Sum each category count once.
- 1 mark: Give the correct requested result, retaining signs, units and any domain restrictions.
Alternative methods: Any complete mathematically valid alternative method with the same restrictions and equivalent exact result is acceptable.
Common error: Check the answer against the original conditions.
(c) · 2 marks
- 1 mark: Distinguish excluded records from retained observations.
- 1 mark: Give the correct requested result, retaining signs, units and any domain restrictions.
Alternative methods: Any complete mathematically valid alternative method with the same restrictions and equivalent exact result is acceptable.
Common error: Keep intermediate values exact until the final step.
Total: 6 marks.