probability distribution

1- According to the Nielsen Company, the mean number of TV sets in a U.S. household in 2008 was 2.83. Assume the standard deviation is 1.2. A sample of 85 households is drawn. Would it be unusual for an individual household to have fewer than 1 TV set?

2- According to the U.S. Energy Information Administration, the mean monthly household electric bill in the U.S. in 2007 was 99.70withastandarddeviationof99.70withastandarddeviationof20. Assume the amounts are normally distributed. In the winter bills can run higher than usual due to colder temperatures. To help customers cope with the higher costs in winter, an electric supplier offers a payment plan for customers with costs in the top 4% of all electric bills. What bill amount would a customer have to exceed to be offered the payment plan?

3- A life insurance company sells a 200,000 1−year term life insurance policy to a 21−year old female for 450. According to the National Vital Statistics Report the probability that the female survives the year is 0.9989. Which of the following is a correct probability distribution for the random variable X, the profit made by the insurance company on this policy.

A. x | P(x)

$450 | 0.0011

-$199,550 | 0.9989

B. x | P(x)

$450 | 0.9989

-$199,550 | 0.0011

C. x | P(x)

$450|0.9989

-$200.000 | 0.0011