Exercise 1-21 Algo The accompanying data set contains three numerical variables, x1, x2, and x3, and one categorical variable x4. Click here for the Excel Data File a. How many observations have x4 values that are less than 3? Answer is complete and correct. Number of 85 observations b. Sort the data by x1 in ascending order. What are the x1, x2, x3, and x4 values of the first observation after the data are sorted? (For x1, round your answer to four decimal places.) x Answer is complete but not entirely correct. Value of x1 0.1982 X Value of X2 78 X Value of X3 23 X Value of X4 3 Vc. Sort the data by x1 In descending order. What are the x1. x2. x3. and X4 values of the first observation after the data are sorted? [For :1, round your answer to four decimal places.} 9 mr II not complete. d. How many missing values are there in x1, x2, X3. and X4? a Mr I: amulet: and camel:- The number of missing values in in 1 o The number of missing values in x; 1 o The number of missing values in x; 1 o The number of missing values in m D o