A random sample of 18 closing prices (to the nearest dollar) from the New York Stock Exchange (NYSE) was taken on August 25, 1998, about one week prior to a 512 point (6.4%) loss in the Dow Jones Industrial Index on August 31, and again using the same stocks on September 15, 1998. Both dates were on a Tuesday. The data are shown below. We'd like to know whether there is convincing statistical evidence of an average change in stock prices on the NYSE between these two dates. The stock price data and some summaries are shown. Consider the two 90% confidence intervals shown in the output for the Aug 25 prices and the Sept 15 prices. Do those two confidence intervals provide convincing statistical evidence that there was a change in average stock price for all NYSE stocks between those two dates? Explain