Brenda’s scores on the first three of four 100-point science tests were 95, 92, and 89. what score does she need on her fourth science test to ensure an average score of at least 93?

If the average of four scores is going to be 93,
then the four scores will add up to  (4 x 93) = 372 .

The first three scores add up to  (95 + 92 + 89) = 276 .

In order to reach a 93 average for four scores,
Brenda needs  (372 - 276) = 96  on the fourth test.
Yay Brenda !  It'll be tough, but you can do it !