A driver records the times (minutes) taken to complete a 50 km lap over 30 laps: Time 23 (frequency 3), 24 (7), 25 (8), 26 (6), 27 (3), 28 (2), 29 (1). What is the sample mean lap time, to 1 decimal place?

Model answer

25.3

Also accepted: 25.3 minutes

Explanation:

\sum fx = 3(23)+7(24)+8(25)+6(26)+3(27)+2(28)+1(29) = 759

. With

n=30

\bar x = 759/30 = 25.3

minutes.

Derived from ZIMSEC Maths Paper 1, June 2007, Q10 (Statistics)

Get the full paper, not just one question

Danho has every sitting for this paper, with your progress tracked question by question, offline.