The time required to finish a test is normally distributed with a mean of 60 minutes and a standard deviation of 10 minutes. What is the probability that a student will finish the test in less than 70 minutes?

The answer is 0.3413 because Explanation:

z = x-u σ, where u=6 0andσ=10.

Therefore the probability student finish the test between 50 to 60 minutes is,

P (50≤x≤60) = P (50-60 10 ≤z≤ 60-60 10)

P (-1≤z≤0) = P (z≤0) - P (z≤-1)

=0.5000-0.1587 = 0.3413