After seeing commercials claiming one can get cheaper car insurance online, a local insurance agent was concerned that he might lose customers. To investigate, he randomly selected profiles (type of car, coverage, driving record, etc.) for 10 of his clients and checked online price quotes for their policies. The comparisons are shown in the accompanying table. Also, his statistical software produced the given summaries. At first, the insurance agent wondered whether there was some kind of mistake in this output. He thought the Pythagorean Theorem of Statistics should work for finding the standard deviation of the price differences-in other words, that SD(Local - Online) =