Calculate the Weighted Average: Student's Grade from 40%, 20%, 15%, and 25% Scores

To find the weighted average grade, follow these steps:

• Step 1: Convert the percentage weights into decimal form:
• 40% to 0.40
• 20% to 0.20
• 15% to 0.15
• 25% to 0.25
• Step 2: Calculate the contribution of each grade by multiplying it by its weight:
• Grade 68 with weight 0.40: $68 \times 0.40 = 27.2$
• Grade 73 with weight 0.20: $73 \times 0.20 = 14.6$
• Grade 94 with weight 0.15: $94 \times 0.15 = 14.1$
• Grade 91 with weight 0.25: $91 \times 0.25 = 22.75$
• Step 3: Sum the contributions:
$27.2 + 14.6 + 14.1 + 22.75 = 78.65$

Since the weights sum up to 100%, the weighted average grade is directly this sum.

Therefore, the student's weighted average grade is $78.65$.