Iq scores are normally distributed with a mean of 100 and a standard of 15. If a certain statistician has an IQ of 140, what percent of the population has a lower IQ?

Respuesta :

Answer:

0.9962

Step-by-step explanation:

The z-score for this problem can be found using the formula

[tex]z=\frac{x-\mu}{\sigma}[/tex]

For our problem, x is 140, μ is 100 and σ is 15:

[tex]z=\frac{140-100}{15}=\frac{40}{15}=2.67[/tex]

Using a z-table, we see what proportion of values are to the right of this. It is 0.9962.