In 2012, the Humane Society reported that 30.4% of all U.S. households own at least one cat. Assuming these results came from a survey conducted among 10,000 U.S. households, what is the 90% confidence interval that estimates the population proportion of U.S. households that own at least one cat? Include a short paragraph stating succinctly, what this confidence interval means. Show all work.
The same report listed the mean annual veterinary cost per household (of those owning at least one cat) as being $191 with a standard deviation of $13.50. Assume that these figures came from a sample of 5000 U.S. households with at least one cat.
a. Find a 98% confidence interval for the actual annual mean veterinary cost among U.S. households with at least one cat. (Show all work and provide detail for technology use).
b. If a household reported annual veterinary costs of $198.50, would that be considered unusual? Support your answer with data.