1.2 USA Today reported that the average credit card debt per US. household was $9,312 in 2004. Assume that the distribution of credit card debt per household has a normal distribution with a standard deviation of $3,000. 3. Determine the percentage of households that have a credit card debt of more than $15,000. b. One household has a credit card debt that is at the 93th percentile. Determine its credit card debt. c. If four households were selected at random, determine the probability that at least half of them would have credit debt of more than $15,000