Answer:
First, when we have a function f(x), an horizontal dilation of scale factor k, is written as:
g(x) = f(x/k)
Then f((2/3)*x) is an horizontal dilation of scale factor 3/2 of the function f(x).
(The graph will be a little bit wider than the graph of f(x))
Also, knowing that f(x) = x^3 + 3
Then:
f((2/3)*x) = ( (2/3)*x)^3 + 3
= (8/27)*x^3 + 3
And the graph of this function is shown below:
