This is an equation, you can't write equations as decimals. I think you're asking for x (as a decimal)?
Add 8 to each side: 4+8= 8+(-8)+3x
12=3x
x=4
This is a whole number so it's already in decimal form
150% of 18 is 27
Divide 27 by 18:

Multiply 1.5 by 100, this will convert the decimal to a percentage:
Answer:2.41 s
Step-by-step explanation:
Given
Stairwell is at a height of 
and Height from where he starts 
Total height boy needs to cover is


using

where 







To do that you'll need the mean and standard deviation of all the scores. Can you provide this info?
For example: Supposing that the mean of these scores were 52 and the standard deviation 3. You'd need to find the "z-score" of 57 in this case.
57 - 52
It is z = ------------ , or z = 5/3, or z = 1.67.
3
Find the area to the left of z = 1.67. Multiply that area by 100% to find the percentile rank of the score 57.
hope it helps you!!!!!!!!!!