Score	Count
(40-50)	2
(50-60)	2
(60-70)	4
(70-80)	4
(80-90)	3
(90-100)	1

What percentage of students earned a grade of less than 90?___%

Round percentage to the nearest whole number

P.S. If you can explain how to do this problem in excel thatwould be greatly appreciated but its not required, thank you!