A science lab runs the same reaction-time experiment once in the morning and once in the afternoon, each with \(30\) trials. The box plots show the reaction...
Question 1 Report
A science lab runs the same reaction-time experiment once in the morning and once in the afternoon, each with \(30\) trials. The box plots show the reaction times, in seconds, recorded in each session.
- Find the interquartile range of the morning reaction times. (1)
- Find the interquartile range of the afternoon reaction times. (1)
- Compare the two sessions, using the medians and interquartile ranges, and state which session had more consistent reaction times, giving a reason. (2)
- State, with a reason, which session was generally faster. (1)
Answer Details
On a box plot, the interquartile range is the width of the box; comparing two sessions uses the median for typical speed (a lower reaction time is faster) and the interquartile range for consistency (a smaller IQR means less spread in the middle half of the results).
- Morning: IQR \(=2.7-2.0=0.7\) seconds [1 mark]
- Afternoon: IQR \(=3.1-1.9=1.2\) seconds [1 mark]
- The morning session has the smaller median (\(2.3\) seconds, against the afternoon's \(2.5\) seconds) and also the smaller interquartile range (\(0.7\), against the afternoon's \(1.2\)); since its IQR is smaller, the morning session had more consistent reaction times. [2 marks]
- The morning session was generally faster, since its median (\(2.3\) seconds) is lower than the afternoon's median (\(2.5\) seconds). [1 mark]
Download The App On Google Playstore
Everything you need to excel in your exams
Personalized AI Learning Chat Assistant
200,000+ Exam Questions Across IGCSE, JAMB, WAEC & NECO
Over 3,900 Lesson Notes
Offline Support - Learn Anytime, Anywhere
Green Bridge Timetable
Literature Summaries & Potential Questions
Track Your Performance & Progress
In-depth Explanations for Comprehensive Learning