Answer:
91 scores
Step-by-step explanation:
Let x be the score meg get on fourth test,
Let the total sum of the scores in four test = 45 + 48 + 56 + x (91) = 149 + x
149 + x = 240
x = 91
So to put this in easier words, (45+48+56+91)/4=91
Hence, she should get 91 scores on the fourth test to get an average score of 60.
I hope this helps you, Enjoy!