On three science tests, Olivia has received scores of 89%, 98%, and 96%. What is the lowest score Olivia can get on her fourth and final science test to achieve an average score of 95%? a
94%
b
97%
c
96%
d
95%

97%

Step-by-step explanation:

Average = x1 + x2 + x3 + x4 + x5 + xN

                                          N

N = total numbers

=> (89 + 98 + 96 + x) / 4 = 95

=> (283 + x) /4 = 95

=> (283+ x) / 4 * 4 = 95 * 4

=> 283 + x = 380

=> 283 -283 + x = 380 - 283

=> x = 97

I divided the sum of all numbers by 4 we are adding 4 numbers.

So, she needs to get 97% in the last test in order to have an average score of 95%