1. A normal population has mean =59 and standard deviation =18

(a) What proportion of the population is greater than 103? (b) What is the probability that a randomly chosen value will be less than 79?

Round the answers to four decimal places.

2. A normal population has mean =35 and standard deviation =6x.

(a) What proportion of the population is between 21 and 31?

(b) What is the probability that a randomly chosen value will be between 28 and 38?

Round the answers to at least four decimal places.

3. A normal population has mean =58 and standard deviation =9. What is the 88th percentile of the population? Use the TI-84 Plus calculator. Round the answer to at least one decimal place.

4. Baby weights: The weight of male babies less than 2 months old in the United States is normally distributed with mean 11.6 pounds and standard deviation 2.9 pounds.

(a) Find the 79th percentile of the baby weights.

(b) Find the 12th percentile of the baby weights.

(c) Find the third quartile of the baby weights.

Use the TI-84 Plus calculator and round the answers to at least two decimal places.

5. Big chickens: The weights of broilers (commercially raised chickens) are approximately normally distributed with mean 1348 grams and standard deviation 171 grams. Use the TI-84 Plus calculator to answer the following.

(a) What proportion of broilers weigh between 1100 and 1204 grams?

(b) What is the probability that a randomly selected broiler weighs more than 1510 grams?

(c) Is it unusual for a broiler to weigh more than 1555 grams?

Round the answers to at least four decimal places.

6. Electricity bills: According to a government energy agency, the mean monthly household electricity bill in the United States in 2011 was $110.56. Assume the amounts are normally distributed with standard deviation $25.00. Use the TI-84 Plus calculator to answer the following.

(a) What proportion of bills are greater than $125?

(b) What proportion of bills are between $83 and $143?

(c) What is the probability that a randomly selected household had a monthly bill less than $113?

Round the answers to at least four decimal places.