Ella’s test grades in her history class are 89, 94, 82, 84, and 98. What score must Ella make on her next test to have a mean test score of 90?
Answer
5
(1 star)
1
Answer:
the answer is 93
Step-by-step explanation:
mean of x,y,z
x+y+z
3 terms
(x+y+z)/3=mean
so
represent next test score as x
89+94+82+84+98+x
count how many terms ther are (6 terms)
mean is 90
(89+94+82+84+98+x)/6=90
add the like terms
(447+x)/6=90
multiply both sides by 6 to clear fraction
447+x=540
subtract 447 from both sides
x=93