Question

The amount of Jen’s monthly phone bill is normally

Answer 1

Answer:

$P(19$

And we can find this probability with this difference and using the normal standard distribution

$P(-3$

Step-by-step explanation:

Let X the random variable that represent the amount of Jen monthly phone of a population, and for this case we know the distribution for X is given by:

$X \sim N(55,12)$  

Where $\mu=55$ and $\sigma=12$

We are interested on this probability

$P(19$

And we can use the z score formula given by:

$z=\frac{x-\mu}{\sigma}$

Replacing the info we got:

$P(19$

And we can find this probability with this difference and using the normal standard distribution

$P(-3$