Question 545784
What is the number grade that I need to get on my final exam to end up with a 72 overall in the class, if I currently have a 86 in the class and the final is worth 30% of my grade.
:
We can do it this way, 
Let x = the final exam grade to have 72 average
{{{((7(86) + 3x))/10}}} = 72
multiply both sides by 10
602 + 3x = 720
3x = 720 - 602
3x = 118
x = {{{118/3}}}
x = 39.3 %, you should be able to handle that, right?