5:14 The index numbers of 4 commodities were 92, 125, 180 and 80, and the weights 12, 7, 6 and 9 are assigned to these commodities. Find the combined arithmetic average index number. 5:14 The index numbers of 4 commodities were 92, 125, 180 and 80, and the weights 12, 7, 6 and 9 are assigned to these commodities. Find the combined arithmetic average index number