Question 176906
<pre><font size = 4 color ="indigo"><b>

1st score = 95
2nd score = 82
3rd score = 93
4th score = 84
5th score = x

Add them up and divide by 5

{{{(95+82+93+84+x)/5}}}

Set that greater than or equal to the desired average, 90

{{{matrix(1,1, (95+82+93+84+x)/5 >= 90)}}}

Simplify the numerator on the left:

{{{matrix(1,1, (354+x)/5 >= 90)}}}

Multiply both sides by LCD of {{{5}}} to 
clear of fractions:

{{{matrix(1,1, 5((354+x)/5)>= 5(90))}}}

Cancel {{{5}}}'s on the left, multiply on
the right:

{{{matrix(1,1, cross(5)((354+x)/cross(5))>= 450)}}}

{{{matrix(1,1, 354+x >= 450)}}}

{{{matrix(1,1, x>= 96))}}}

So it'll take a score equal to or greater than 96 
on the 5th test to bring Candice's average up to 90.

Edwin</pre>