Answer:
a. z-score = -1.2
b. The age 23 years old is -1.2 standard deviations below the mean
c. The age is not unusual
Step-by-step explanation:
a. Transformation to z-score
Mathematically;
z-score = (x - μ)/σ
where σ and μ are the standard deviation and the mean respectively.
From the question, x = 23, μ = 27.2 and σ = 3.5
Let’s put these into the equation;
z-score = (23-27.2)/3.5 = -1.2
b. Interpretation of result
The interpretation is that 23 years old is -1.2 standard deviations below the mean
c. Determination
The age is not unusual. This is because any z-value below -2 or above 2 is considered unusual
-1.2 is above -2 and thus it is not unusual