Question

The distribution of bladder volume in men is approximately normal with mean 550 ml and standard deviation 100 ml. what percent of men have a bladder volume larger than 450 ml? round to the nearest whole number.

Answer 1

To solve this, we use the z-test.

z = (x – u) / σ

when x = 450

z = (450 – 550) / 100

z = -1

 

We use the standard distribution tables to find for P.

P = 0.1587

 

Since we are looking for values greater than x = 450, therefore:

1 – 0.1587 = 0.8413

 

This means that 84.13% have bladder volume larger than 450 mL.