How can i create a distribution curve over a histogram.

suppose I have created a histogram: x=[2948,2577, 2936, 3385, 6435, 4591, 4243, 4491, 4485, 4509, 4480, 4594, 4436, 4347, 4419, 4546, 4835, 4825, 4672, 44667, 4193]; n=12; h=histogram(x,n)

1) how can I scale it so it has an area of 1 so I can compare a distribution to it

2) how can I compare a poisson distribution, exponential, normal and any other distribution it may be likely to satisfy?

I want to create it above the histogram thanks

any other statistical inferences ideas to analyse my data would be useful