If the student has grades of 62,67,75, and 89 on the first four exams, what is the student's grade before taking the the final exam? and what is the lowest score the student can earn on the last exam to get a C (70) in the course?
Current grade = (62+67+75+89)/4 = ?
Total grade = (62+67+75+89+x)/5 = 70
Solve for x.
To calculate the student's grade before taking the final exam, you need to find the average of the first four exam grades. The formula for average is:
Average = (Sum of grades) / (Number of grades)
In this case, the student has grades of 62, 67, 75, and 89 on the first four exams. To find the sum of these grades, you add them up:
Sum = 62 + 67 + 75 + 89 = 293
Then, divide the sum by the number of grades (4 in this case) to find the average:
Average = 293 / 4 = 73.25
So, the student's grade before taking the final exam is 73.25.
Now, let's calculate the lowest score the student can earn on the last exam to get a C (70) in the course. Since the final exam has a weight on the overall grade, you need to account for that.
Assuming the final exam has a weight of x (out of 100), the average will be calculated as follows:
Average = (Average of first four exams * 0.8) + (Final exam * 0.2)
Given that the desired average is a C (70 out of 100), you can set up the equation:
70 = (73.25 * 0.8) + (Final exam * 0.2)
To isolate the "Final exam" variable, you can solve for it:
Final exam * 0.2 = 70 - (73.25 * 0.8)
Final exam * 0.2 = 70 - 58.6
Final exam * 0.2 = 11.4
Now, divide both sides of the equation by 0.2 to find the value of the Final exam:
Final exam = 11.4 / 0.2
Final exam = 57
Therefore, the lowest score the student can earn on the final exam to get a C (70) in the course is 57.