Amanda and Barbara each bought blue salvias and zinnias. Amanda spent $261 on 12 blue salvias and 15 zinnias. Barbara spent $218 on 6 blue salvias and 20 zinnias. What is the cost of one blue salvia and the cost of one zinnia

Monthly water bills for a city have a mean of $108.43 and a standard deviation of $36.98. find the probability that a randomly selected bill will have an amount greater than $173, which the city believes might indicate that someone is wasting water. would a bill that size be considered unusual?