Question

Clare analyzes oil prices in her economics class. She finds that the mean oil price between 1988 and 2002 is $27 per barrel with a standard deviation of $5.50 per barrel. Select the z-score for a price of $35.25 per barrel. (Select one answer)
0.67

1.5

8.25

-8.25

Answer 1

Answer:

Option 2: 1.5 is the correct answer.

Step-by-step explanation:

Given information is:

Mean = μ = $27

SD = σ = $5.50

A z-score simply tells us how far a selected data value from the mean is.

Z-score is denoted by z and is given by the formula:

$z = \frac{x-mean}{SD}$

Let x = $35.25

Putting the values of mean and SD we get,

$z = \frac{35.25-27}{5.50}\\z = \frac{8.25}{5.50}\\z =1.5$

The value of z-score for a price of $35.25 per barrel is 1.5

Hence,

Option 2: 1.5 is the correct answer.