Lets put the 36 into 8ths because 8ths are the smallest "unit." 1 = 8/8 so if we do 36*8, we get 288. Put the 288 over the 8 to make 288/8. Now lets do the same for the 7 and 1/2 and 9 and 1/8. 7*8= 56/8. Now take the 1/2 and multiply the denominator and the numerator by 4. you get 56/8 and 4/8. Add them together. You get 60/8. Now lets do 9 and 1/8. 9*8 is 72. Put the 72 on top, 72/8. Add the 1/8 to the 72/8. You get 73/8. You now have 3 numbers. 288/8, 60/8, and 73/8. Lets arrange them the way the problem wants us to. 288/8 - 60/8 - 73/8 = X. Subtract. You get 155/8. Now how many times does 155 go into 8? About 19 times. Now lets figure out the fraction. We have 3 leftover, so 3/8. The answer is 19 and 3/8. Hope I helped and taught ya something :)
Assuming a standard normal distribution, the positive value of interest will be that corresponding to the 50 + 36/2 = 68th percentile. A suitable probability calculator will give that value as 0.46770.
The values that are within ±0.46770 standard deviations from the mean will have a probability of 0.36.
