Part 1: The following numbers below represent heights (in feet)of 3-year old elm trees: 5.1, 5.8, 6.1, 6.2, 6.4, 6.7, 6.8, 6.9,7.0, 7.2, 7.3, 7.3, 7.4, 7.5, 8.1, 8.1, 8.2, 8.3, 8.5, 8.6, 8.6,8.7, 8.7, 8.9, 8.9, 9.0, 9.1, 9.3, 9.4. Assuming that the heightsof 3-year old elm trees are normally distributed, find a(two-sided) 90% confidence interval for the mean height of 3-yearold elm trees.
Part 2:Assuming that the heights of 3-year old elm trees arenormally distributed, use the data in the previous problem to testwhether the average height of 3-year old elm trees is greater than7.5 feet, at significance level 0.05. Also, what is the p-value ofthe test?
