Answer:
C. -0.34
Explanation:
We have that for a normal distribution, the value of z can be calculated using the following formula:
z = (x - m) / sd
where x is the value to evaluate, m the mean and sd the standard deviation, we have those values x = 16.3, m = 17.4 and sd = 3.2
if we replace we have:
z = (16.3 - 17.4) /3.2
z = -0.3437
if we round to 2 decimal places, it would be -0.34, that is, the answer is C.