The SP-6 index (a fictitious index) is used by many investors to monitor the general behavior of the stock market. It has a base value set equal to 100 at January 1, 1975. In the accompanying table, the closing market values for each of the 6 stocks included in the index are given for 3 dates. a. Calculate the value of the SP-6 index on both January 1, 2013, and June 30, 2013, using the data presented here. b. Compare the values of the SP-6 index calculated in part a and relate them to the base index value. Would you describe the general market condition during the 6-month period January 1 to June 30, 2013, as a bull or a bear market?