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

65.54% (nearest hundredth)

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%