When Adrian runs the 400 meter dash, his finishing times are normally distributed with a mean of 77 seconds and a standard deviation of 3 seconds. What is the probability that in a given race, his finishing time will be faster than 75 seconds, to the nearest thousandth?

Respuesta :

Answer:

0.749

Step-by-step explanation:

We start by calculating the z-score

Mathematically:

z-score = (x-mean)/SD

z-score = (75-77)/3 = -2/3 = -0.67

The probability we want to calculate is;

P( X > -0.67)

we can use the standard normal distribution table for this

Using this table, the probability has a value 0.74857 which is 0.749 to the nearest thousandth