This is not an answer, but I think it's too important to leave as a comment.
I strongly urge you to rethink your goals for this course.
Your goals should be to prepare your students to teach mathematics in elementary schools.
The Praxis test is a not terrible minimum measure of this ability, but, frankly, it's not that good a measure, and many people who pass the Praxis are still pretty terrible teachers of elementary school math, particularly if they have been taught to the test without really understanding what they are learning.
My impression is that half of US university students don't understand multiplication of integers, in the sense that they don't understand that if you repeat a process that takes m steps n times, you end up having to do m*n total steps. In many cases (and this is corroborated by what many elementary teachers say about themselves and each other), this is because they had 3rd and 4th grade teachers who don't understand this either. (Never mind addition of fractions. Basically no one understands that.)
Your job is to help stop this cycle of ignorance, not prepare people for a standardized test.