Question

The mean amount spent by a family of four on food is $500 per month with a standard deviation of $75. Assuming that the food costs are normally distributed, what is the probability that a family spends less than $425 per month?​

Answer 1

Answer:

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

And replacing we got:

$z=\frac{425-500}{75}= -1$

And we can calculate this probabilit using the normal standard distribution or excel and we got:

$P(z$

Step-by-step explanation:

If we define the random variable of interest "the amount spent by a family of four of food per month" and we know the following parameter:

$\mu = 500, \sigma = 75$

And we want to find the following probability:

$P(X$

And we can use the z score formula given by:

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

And replacing we got:

$z=\frac{425-500}{75}= -1$

And we can calculate this probabilit using the normal standard distribution or excel and we got:

$P(z$