Based on the information provided, if 28 students earned a C on the test and that represents 56% of the total number of students, we can calculate the total number of students enrolled in the calculus course.
Let's set up a proportion to solve for the total number of students:
28 students is to 56% as X students is to 100%.
Using cross multiplication:
28 * 100% = X * 56%
Simplifying:
2800% = 56X
Dividing both sides by 56:
50 = X
Therefore, there are 50 students enrolled in the calculus course.