A student needs a 70 average in order to pass a class. Quizzes count 30% &tests count 70%. If a student has a quiz grade at end of semester of 100

Question

What does the test average need to be in order to have a 70 grade at end of semester?

Answer 1

Hi Rachel,

 

This is a weighted average problem:

 

Quizzes count for 30% of your grade while test count for the remaining 70%.

 

We can calculate what test average will give you a 70% in the class.

 

Here is the equation:

 

Final Grade = quiz grade* % that quizzes count + test grade*% that tests count.

 

Now let's substitute.

 

70% = 100%*30%+test grade average * 70%

 

Now let's solve for test grade average:

 

test grade average = (70%-100%*30%)/(70%)

 

test grade average is about  57.2%

 

As long as the test grade average is greater than 57.2%, the final score will be 70% or above