Which of the following are true about z-scores?

I: They are positive whenever X is greater than the mean in a normal distribution.

II: The standard normal distribution, which is the distribution of all z-scores, has a mean of 0 and standard deviation of 1.

III: They can be found by taking X, subtracting the mean, and dividing the result by the standard deviation.

	a.	I only
	b.	II only
	c.	III only
	d.	I and II only
	e.	I and III only
	f.	II and III only
	g.	I, II, and III
	h.	None of these