Question

Cerebral blood flow (CBF) in the brains of healthy people is normally distributed with a mean of 74 and a standard deviation of 16

What proportion of healthy people will have CBF readings between 60 and 80?

Answer 1

About 45.35% of healthy individuals exhibit cerebral blood flow between 60 and 80, given a mean of 74 and a standard deviation of 16.

How to find the proportion?

Using the Z-scores:

`\[ Z_{\text{lower}} = \frac{{60 - 74}}{{16}} = -0.875 \]`

`\[ Z_{\text{upper}} = \frac{{80 - 74}}{{16}} = 0.375 \]`

The area to the left of Z = -0.875 is approximately 0.1908, and the area to the left of Z = 0.375 is approximately 0.6443.

Now, find the area between these two Z-scores:

Proportion = 0.6443 - 0.1908

Proportion ≈ 0.4535

So, approximately 45.35% of healthy people will have CBF readings between 60 and 80.