Question

Assume the annual day care cost per child is normally distributed with a mean of ​$9000 and a standard deviation of ​$1000. What percent of day care costs are more than ​$8600 ​annually?

Answer 1

Answer:

65.54% (nearest hundredth)

Step-by-step explanation:

Given:

• $\sf \mu=9000$

• $\sf \sigma=1000$

$\sf X \sim N(\mu, \sigma^2)\implies X \sim N(9000,1000^2)$

P(X > 8600) = 1 - P(X ≤ 8600)

                    = 1 - 0.3445782584

                    = 0.6554217416

                    = 65.54%