The grade of Olivia in the Maths class can be found by dividing the obtained marks by the total marks.
The obtained marks are below
Test 1 = 83
Test 2 = 95
Midterm = 84
Test 3 = 93
Test 4 = 84
Test 5 = 92
Final = 90
So the obtained marks are
Obtained marks = 83+95+84+93+84+92+90 = 621
The total possible marks are
Total marks = 7*100 = 700 (since there are 7 assessments each worth 100 marks)
![\begin{gathered} grade=\frac{\text{obtained marks}}{\text{total marks}}*100\% \\ grade=(621)/(700)*100\% \\ grade=88.71\% \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/pcy4jwlfsx005hz0718ezuh0osqd0esey5.png)
Rounding off to the nearest percent, we get
![grade=88.71\%=89\%](https://img.qammunity.org/2023/formulas/mathematics/college/ceuuh2fwpl5df7kegfnrii0qelkkrnxc2e.png)
Therefore, Olivia's grade in Maths class is 89%
Option D is the correct answer.