Maria has scores of 96, 86, and 78 on three test. what must her average score be in order for her to have an average of at least 90?

Marks scored in three tests = 96 , 86 , 78

Total of these scores = 260

Let the score that needs to be scored be = x

Average needed of four scores = 90

Average = total scores added of all subjects/number of subjects

Hence, a score of 100 is required to make an average score of 90.