Question

The results of the mid-term exam in an Algebra I class were as follows: 25 students scored an average of 85, and the remaining 15 students scored an average of 70. What was the overall average score for the entire class?

a) 77
b) 80
c) 82
d) 75

Answer 1

The overall average score for the class is found by calculating the weighted mean, resulting in an overall average score of approximately 79. The closest answer choice is b) 80.

Step-by-step explanation:

The overall average score for the entire class can be calculated using the weighted mean formula. The average score for the 25 students is multiplied by the number of students, and the same is done for the 15 other students.

These products are then summed and divided by the total number of students to find the overall average score.

Here is the calculation step-by-step:

1. Calculate the total score for each group: (25 students × 85 average) + (15 students × 70 average).
2. Combine the total scores to get the grand total: 2125 + 1050 = 3175.
3. Divide the grand total by the number of students to get the overall average: 3175 ÷ (25 + 15) = 3175 ÷ 40.
4. The overall average score is 79.375, which rounded to the nearest whole number is 79.

The answer choice closest to 79 is b) 80.