I have a 62,75,90 on my history exams what do I need on the fourth one to have a mean of 80

Mean of the 5 is the average

lets solve for what score gets 80

and lets say last score is x

so

(sum of scores) / 4=80

(62+75+90+x) / 4=80

(227+x) / 4=80

times 4 both sides

227+x=320

minus 227 from both sides

x=93

yo need a 93

good luck