U 1 2
The table gives information about the times taken, in minutes, by 22 students to
cycle a race.
Time (t minutes) Frequency
15 4
20 1
25 7
30 10
Work out an estimate for the mean time.
Give your answer in minutes and correct to 3 significant figures.

pay attention in your classes and concentrate the best thing you can do to raise your test scores is to pay attention when you're supposed to be learning the material: in class!

take good notes.

do your homework.

use mnemonics and other tricks.

do practice tests.

note: the best i know.

5/20 so 25%

step-by-step explanation:

sounds & other waves originate from any vibrating object