A pine tree measured 40 1/2 feet tall. Over the next 7 1/2 years, it grew to a height of 57 feet. During the 7 1/2 years, what was the average yearly growth rate of the height of the tree?

A pine tree measured 40 1/2 feet = (40 + 1/2) feet = (80+1) / 2 ft=81/2 feet

it grew to a height of = 57

7 1/2 years = (14+1) / 2=15/2 year.

Then, during 7 1/2 years the pine tree has grown=57 ft - 81/2 ft=

= (114-81) / 2 ft = 33/2 ft.

average yearly growth = (number of meters that the pine tree has grown) / number of years

average yearly growth = (33/2) ft / (15/2) years=33/15 ft / years=2.2 ft/year.

solution. 2.2 ft / year.