SOLUTION: Lizzy went bowling. She bowled 3 games with a mean score of 84. If her first 2 games had a mean of 81, what would she have to bowl in her final game?

Algebra ->  Average -> SOLUTION: Lizzy went bowling. She bowled 3 games with a mean score of 84. If her first 2 games had a mean of 81, what would she have to bowl in her final game?      Log On


   

Question 1114054: Lizzy went bowling. She bowled 3 games with a mean score of 84. If her first 2 games had a mean of 81, what would she have to bowl in her final game?
Found 2 solutions by amalm06, greenestamps:
Answer by amalm06(224) About Me  (Show Source):
You can put this solution on YOUR website!
First two games: %28x%2By%29%2F2=81 ---> x%2By=162
All three games: %28x%2By%2Bz%29%2F3=84 ---> %28162%2Bz%29%2F3=84 ---> z=90

So she would have to bowl 90 in her final game (Answer)

Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


Here is a method you can use for problems like this involving the average (mean) of numbers that are close together....

Her average was 84; her average for the first two games was 81.
That average for her first 2 games is 3 less than her final average.
That means that after the first 2 games she is a total of 2*3=6 points short of her final average.
And that means she has to be 6 points ABOVE her final average in the third game.

So the score in her last game must be 84+6 = 90.