function pareto( rand, alpha, beta ) {
	return beta / pow( rand(), 1.0/alpha );
}
Returns a pseudorandom number drawn from a Pareto (Type I) distribution.

@private
@param {PRNG} rand - PRNG for uniformly distributed numbers
@param {PositiveNumber} alpha - shape parameter
@param {PositiveNumber} beta - scale parameter
@returns {NonNegativeNumber} pseudorandom number