Answer: 95.45 %
Step-by-step explanation:
Given : The distribution is bell shaped , then the distribution must be normal distribution.
Mean : 
Standard deviation :
The formula to calculate the z-score :-

For x = 13

For x = 19

The p-value = 

In percent, 
Hence, the percentage of data lie between 13 and 19 = 95.45 %
I believe it would be 12/18 so that would be 2/3 and 0.6 in decimal form
let's recall the vertical line test, if a vertical line hits the graph or points twice, then is NOT a function. Check the picture below.
A variable next to any number means to multiply, so we would do the inverse operation -- We would divide 0.48 by 0.6, which is 0.8. Therefore, W=0.48. To check your work, multiply 0.6 by 0.8, and what do you know? It's 0.48! :)