3 (20 points) For households that had credit card debt, the average debt in 2016 was $16,355. Assume that credit card debt per household has a normal distribution with a standard deviation of $3,300. a. Determine the percentage of households that have a credit card debt of more than $20,000. b. One household has a credit card debt that is at the 80th percentile. Determine its credit card debt.

4 (10 points) A random sample of size n = 500 yields 80 successes. Calculate the 90% confidence interval for , the successful rate.

5 (20 points) Suppose for Tesla Model 3 electric cars, the mean miles of range from a full charge is 400 miles, and the standard deviation is 30 miles. a. Given the above mean and standard deviation, what is the probability that 100 drivers will average more than 405 miles from a full charge? b. Suppose 1,000 drivers were randomly selected. What is the probability the average obtained by these drivers will exceed 405 miles?