Answer: The answer that I got for z was 0.111575, which when you round it to the hundredths place would be 0.11
In the left hand side, you're multiplying 7.8 by
In the right hand side, you're multiplying again 7.8 by a mysterious number.
So, the unknown number must be
Every number remains unchanged when multiplied by 1, so the answer is 3.6
Fifth grade has 24 students per each teacher.
Sixth grade has about 23 students per teacher.
Sixth grade is lower.