Answer
The answer and procedures of the exercise are attached in the following archives.
Step-by-step explanation:
You will find the procedures, formulas or necessary explanations in the archive attached below. If you have any question ask and I will aclare your doubts kindly.
Answer: 34%.
By definition of normal distribution, ≈68% of the data is within 1 standard deviation of the mean. Therefore 68% of IQs are between 85 and 115, and half of that is on the lower end, 85 to 100.
First of all, to simplify a number/fraction, you must find a common multiple.
Both 12 and 42 is divisible by 6

=

since 6 goes into 12, two times and goes into 42, 7 times. The answer is

when simplified.
If we take 12450 to be the 100%, what is 622.50 off of it in percentage then? let's check.
I think it would be sometimes true.