For example, Emily received a 67 on her first economics exam, which counts for 20% of her grade; an 84 on her second exam, which counts for 30% of her grade; and a 78 on her third exam, which counts for 50% of her grade. What is her weighted average in the class

Based on the weights assigned to these grades, Emily's weighted average in the class would be 77.6 marks.

= ∑ (Percentage of grade x Score in exam)

Solving gives:

= (20% x 67) + ( 30 % x 84) + (50% x 78)

= 13.4 + 25.2 + 39

= 77.6

Emily's weighted average is 77.6 marks.

Find out more on weighted average at link.

77.6

Step-by-step explanation:

Given the data:

Weighting :

First exam = 20% ; second exam = 30% ; third exam = 50%

Scores :

First exam = 67 ; second exam = 84 ; third exam = 78

Weighted Average :

Σ(Weight * Score)

Σ[(0.2 * 67) + (0.3 * 84) + (0.5 * 78)]

13.4 + 25.2 + 39

= 77.6

slope intercept form is y = mx + b