Find final grade average for a class.

Question

Carrie has an 88% average in biology class after all four of the lab grades were recorded. If the final exam counts twice as much as the four lab grades, what percent must Carrie make on the final exam to have a final average of 90% for her biology grade?

Answer 1

Multiply 88 by 4 to get the point total for the first 4 tests. 88 x 4 = 352

 

Since the last is worth double it like Carrie is taking 6 total tests. so multiply 90 by 6. 90 x = 540

 

Subtract totals 540  - 352 = 188.  This is the point value 188 out of 200 points.  

 

Which is 94%