Answer:
99 points
Step-by-step explanation:
Average of a data a is the sum of the data divided by the number of data.
Average = sum of data ÷ number of data
A = T/n .....1
For the average of 5 test to be 90.
The total sum of score must be;
Number of tests n = 5
Average A = 90
Substituting into equation 1
90 = T/5
T = 90×5 = 450 points
The total score must be equal to 450 point to have an average of 90 points
The sum of the first four test is;
88+84+88+91 = 351
Let x represent the first score,
351 + x = 450
x = 450 - 351
x = 99 points
The minimum score she can get in the fifth test is 99 points
