Task instructions
Solve efficiently and select the best answer. Show your working in the practice workspace.
Group A has mean 12 and Group B mean 15. Which statement must be true?
A. The total per observation is higher in Group B on average.
B. Every B value exceeds every A value.
C. Both groups have the same size.
D. Group B has lower variance.
Practice workspace
Write notes or your response
02:00
Reveal answer key / expected response
A — The total per observation is higher in Group B on average.
Suggested approach
Translate the statement into mathematical form; compute; check units and reasonableness.
Official-style scoring criteria
Correct result and sound quantitative reasoning.