Question 329074
Your total score now is 75 + 90 + 77 + 88 = 330
You have 4 scores.
Add one more score and you'll have 5 scores.
Divide that by 5 and you'll get the new average.
You want the new average to be >= 83.


Let x be the fifth score.


Your formula is (330 + x) / 5 >= 83


This will give you 5 scores that, divided by 5, will give you an average that is greater than or equal to 83.


Multiply both sides of that equation by 5 to get:


330 + x >= 83 * 5 which becomes:


330 + x >= 415


Subtract 330 from both sides of the equation to get:


x >= 415 - 330 which becomes:


x >= 85.


You need to get 85 or more to have an overall average of 83.


Your old total is 330.


Add 85 to it to get a new total of 415.


Divide 415 by 5 and you get an average of 85.