2. I surveyed each house on the block to determine how much we are spending on Halloween treats. The distribution below represents the results in dollars. $Spent mid 50-59 54.5 1 40-49 44.5 2 30-39 34.5 5 20-29 24.5 12 10-19 14.5 7 0-9 4.5 7 a) Calculate the 90% confidence interval of the mean and present it in a sentence that shows your understanding of the meaning of the confidence interval. b) Calculate whether there has been a significant increase over the average $18 reported in the neighborhood newspaper. State the hypotheses, alpha, df, and critical value. Write a report, including all necessary information, about your results.