Problem 3: Suppose we want to estimate the average height of buildings in a city using the number of floors as an auxiliary variable. We have the following data Buildings 12 3 4 5 Number of floors 10 28 7 15 17 Height (in metre) 52 134 37 70 81 Assume that the average number of floors of buildings in this city is 18 and the number of buildings is very large. 1. Estimate the average height of buildings in a city using regression estimation. Compute its standard error. 2. Construct the 95% confidence interval for the average height of buildings in this city.