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?

• alexalwaysneedshelp:

  First subtract how tall it was 7 1/2 years ago from how tall it is now.57 - 40 1/2 =57 -  40.5 =  16.5 or 16 1/2So in the 7 1/2 years the tree grew 16 .5 or 16 1/2 feet. To get the average yearly growth for the 7 1/2 year period you have to divide the 16 1/2 feet by 7 1/2 years .It makes it much easier if you change the fractions to decimals. 16 1/2 = 16.57 1/2 = 7.516.5  ÷  7.5  = 2.2 or 2 1/5 feet per year! :)