Question 274682
Going into the final exam, which will count as two tests, Ameilia has test scores of 79,86,72,59 and 94. 
What score does Amelia need on the final in order to have an average score of 80?
:
Let x = final exam score
Counts as two tests, so call it 2x
:
{{{(79 + 86 + 72 + 59 + 94 + 2x)/7}}} = 80.
add em up, and mult by 7
2x + 390 = 7(80)
:
2x = 560 - 390
x = {{{170/2}}}
x = 85 to have an 80 average