Answer: the z score is - 1.5
Step-by-step explanation:
Since the time required to finish a test is normally distributed, we would apply the formula for normal distribution which is expressed as
z = (x - µ)/σ
Where
x = time required to finish the test
µ = mean time
σ = standard deviation
From the information given,
µ = 60 minutes
σ = 10 minutes
We want to find the z-score for a student who finishes the test in 45 minutes
For x = 45,
z = (45 - 60)/10 = - 15/10 = - 1.5