Answer:
The correct answer is z = 1.2
Step-by-step explanation:
μ or average income = US$ 3,000
σ or standard deviation = US$ 250
Income in a given month = US$ 3,300
For calculating the z score, we use the following formula:
z = (x – μ) / σ
z = (3,300 – 3,000 / 250)
z = 300/250
z = 6/5 = 1.2
Interpreting z
A Z score tells us how many units of standard deviation (1.2 in this case)from the average a given score is, that is, we do not count in quantity of points, but in quantities of standard deviations. To use the Z score we require the distribution to be normal and to know the average and standard deviation of the scores.
