Answer questions 2&3 only and please show all work

1. Raw data set for variables X and Y are: X : 50, 43, 45, 60,38 For Y we have 23, 30, 24, 20, 32. Compute the following a. The mean value of both variables X and Y b. The standard deviations (st.d) for X and Y c. The covariance of X and Y . 2. Suppose an economist collected a data set comprising 400 data points (or observations) . From a mathematical point of view, what the minimum number of classes she may have in her bar chart? Do the math! 3. Suppose X was 60 Y was 23, and when X rose to 75 Y jumped to 30. Forecast the value of Y if X increases 90. You must compute the terms a and b in the equation Y = a + bx before making your forecast. 4. The words residuals and error term are interchanged frequently in econometrics although they are slightly different. Show their differences. 5. Construct a bar chart showing the relative frequency of these data points and show important statistics: 45, 63, 33, 26, 30, 41, 63, 33, 40, 30, 42, 30, 60, 57, 60, 57, 53, 49, 49, and 27. Take notice; these are raw data