The table below gives the approximate heart a person should maintain while exercising at 85% intensity.

Given Information:  

Number of students = n = 200  

Mean = μ = 8 minutes

Standard deviation = σ = 1 minute  

Required Information:  

P(X > 9) = ?  

P(X > 9) = 15.87 %

Explanation:  

Let X time in hours to run one mile is a random variable that has a Normal distribution with mean of 8 minutes and standard deviation of 1 minute.

We want to find out the probability that a student will take longer time than Mike (9 minutes) to run a mile.

P(X > 9) = 1 - P(Z < (x - μ)/σ)

P(X > 9) = 1 - P(Z < (9 - 8)/1)

P(X > 9) = 1 - P(Z < 1)

From the z-table , the z-score corresponding to 1 is 0.84134

P(X > 9) = 1 - 0.84134

P(X > 9) = 0.15866

P(X > 9) = 15.87 %

Therefore, there is 15.87% probability that a student will take longer time than Mike that is 9 minutes.