Answer:
Jessica needs to score at least 88.2 (or 88) on her last test.
Explanation:
So, her average so far is the sum of the five scores divided by the number of tests she has taken so far.
(87 + 81 + 85 + 90 + 78)/5 = 84.2
(87 + 81 + 85 + 90 + 78)/5 < 85 :(
She will not get into that college if she doesn't increase her average on the last test.
85 - 84.2 = 0.8
0.8(5) = 4.0
On her last test, she needs to score 4 points higher than her current average in order to get into the college.
84.2 + 4 = 88.2
Hope this helped :)