2026 TPSS P2 Q8

A study was conducted on the cognitive skills of adults with age. The study recorded the time 80 adults spent solving a number puzzle. The cumulative frequency curve shows the distribution of the time taken.

1. Use the curve to estimate
   1. the median time taken,[1]
   2. the interquartile range of the time taken.[2]
2. 20% of the adults took more than \(n\) seconds to solve the puzzle. Find \(n\).[2]
3. The same group of adults were each given a word puzzle to solve. The box-and-whisker plot shows the distribution of the time taken.
   Make two comparisons between the performances of the adults in solving the two puzzles.[2]