Question

Need help fast!!! Algebra question!!!

Answer 1

It is B, becuase all numbers lower than 99 don't give you a percent higher than 98%.

Answer 2

AVERAGE between 90 and 100%
means not including 90 and 100% but not including 90 or 100%


average=(sum of values in set)/(how many values in the set)

so
4 exams, so there are 4 values
average=(sum)/4

the sum is the known+unknwon
sum=76+99+86+x

so
90<average and average <100
or
90<average<100


lets say average=a

a=sum/number
a=(76+99+86+x)/4

90<(76+99+86+x)/4<100
90<(76+99+86+x)/4 and (76+99+86+x)/4<100

solve each for x and find intersection

90<(76+99+86+x)/4
times 4 both sides
360<261+x
minus 261 both sides
99<x


(76+99+86+x)/4<100
times 4 both sides
261+x<400
minus 261 both sides
x<139


so

99<x<139
since max score is 100
99<x<100

interval notaion is
[99,100]


answer is 2nd one