Question: Plotting random points along a curve

I'm plotting some random points along a curve but I'm not sure of a couple of things so I have a few questions.

Using a simple curve like x for example.  First I'll choose some random numbers, 100, between -8 and 8, but I also want a couple of decimal points otherwise random integer values will only give me a maximum of 17 points.  So is the best way to do that like this?

with(plots):
a:=[seq((rand(-800..800)(i))/100,i=1..100]    # These will be my x point values;

Then I'll calculate the corresponding y-values for the x equation
b:=[seq(a[i]^2,i=1..nops(a))]  # The y values;

Next I'll combine the values into a third variable and plot the results with pointplot
c:=seq([a[i],b[i],i=1..nops(a));
pointplot({c});

I'm sure there's an easier different way or a more elegant way to do it.