The dartboard below has 3 rings and a bull's-eye. The entire board has a radius of 8 inches. The bull's-eye has a radius of 2 inches. Each ring has
a radius 2 inches larger than the ring before it.
A dart is randomly thrown at the dartboard. What is the probability
that it will land in the bull's-eye or the unshaded ring?
or the 2nd ring?

$69811

Step-by-step explanation:

Given : A survey organization, as part of the United States Census Bureau, conducts a yearly census similar to the one taken every ten years, but with a smaller percentage of participants.

One of these surveys estimates with 90% confidence that the mean household income in the U.S. falls between $69,702 and $69,920.  (1)

We know that the confidence interval is given by :-

Point estimate of mean  ± Margin of error

From (1) , we have

Point estimate for mean  -Margin of error = $69,702   (2)

Point estimate for mean  +Margin of error = $69,920      (3)

Add (2) and (3), we get

2 (Point estimate for mean) = $139622

Divide both sides by 2, we get

Point estimate for mean=$ 69811

Therefore , the point estimate for mean U.S. household income. =  $ 69811