I tried working it out, but I just keep getting the wrong answer!!
Johnny had 3 projects for his english subject, he has completed 2 projects and is yet to complete his third project. Each project has a different weighting and Johnny would like to calculate what mark he needs to achieve in the third project to pass the subject.
NOTE: Assuming a pass equates to 50% of the total marks
Weightings are as follows
Project 1: 25% Johhny recieved: 18/25
Project 2: 40% Johnny recieved: 28/40
Project 3: 35% Johnny recieved: ?????
What mark does Johnny need to achieve in Project 3 in order to pass this unit?
THANKYOUUU
Johnny had 3 projects for his english subject, he has completed 2 projects and is yet to complete his third project. Each project has a different weighting and Johnny would like to calculate what mark he needs to achieve in the third project to pass the subject.
NOTE: Assuming a pass equates to 50% of the total marks
Weightings are as follows
Project 1: 25% Johhny recieved: 18/25
Project 2: 40% Johnny recieved: 28/40
Project 3: 35% Johnny recieved: ?????
What mark does Johnny need to achieve in Project 3 in order to pass this unit?
THANKYOUUU
-
Calculate a weighted average of the three grades:
Project 1: 18/25 = 0.72 = 72%
Project 2: 28/40 = 0.7 = 70%
Project 3: x
Average them:
(0.25 * 72) + (0.4 * 70) + (0.35 * x) = 50
Multiply out:
18 + 28 + 0.35x = 50
Subtract 18 and 28 from both sides:
0.35x = 4
Divide both sides by 0.35:
x = 4 / 0.35 = 11.43
He can score as low as 12% and still get a 50% for the course.
Check:
18 + 28 + (0.35 * 12) = 46 + 4.2 = 50.2
18 + 28 + (0.35 * 11) = 46 + 3.85 = 49.85
Project 1: 18/25 = 0.72 = 72%
Project 2: 28/40 = 0.7 = 70%
Project 3: x
Average them:
(0.25 * 72) + (0.4 * 70) + (0.35 * x) = 50
Multiply out:
18 + 28 + 0.35x = 50
Subtract 18 and 28 from both sides:
0.35x = 4
Divide both sides by 0.35:
x = 4 / 0.35 = 11.43
He can score as low as 12% and still get a 50% for the course.
Check:
18 + 28 + (0.35 * 12) = 46 + 4.2 = 50.2
18 + 28 + (0.35 * 11) = 46 + 3.85 = 49.85