Answer and Step-by-step explanation:
To calculate the student’s weighted mean grade, we need to find the average of her four regular test grades and then multiply each component of her grade by its respective weight.
The average of her four regular test grades is (84 + 78 + 84 + 72) / 4 = 79.5.
Her weighted mean grade is calculated as follows:
Weighted mean grade = (0.4)(79.5) + (0.3)(78) + (0.1)(86) + (0.2)(87) = 31.8 + 23.4 + 8.6 + 17.4 = 81.2
So, her weighted mean grade is approximately 81.2 when rounded to one decimal place.