Question

This table shows the number of miles that Sharon rode her bicycle in six weeks. If the mean number of miles she rode is 30, find the number of miles she rode in Week 3.
Week 1    21
Week 2   34
Week 3    ?
Week 4   25
Week 5   37
Week 6   22

Answer 1

(21 + 34 + x + 25 + 37 + 22) / 6 = 30
(139 + x) / 6 = 30 .....multiply both sides by 6
139 + x = 30 * 6
139 + x = 180
x = 180 - 139
x = 41......so during week 3, she rode her bike 41 miles