Since 2000, the Toyota Camry, Honda Accord, and Ford Taurus have been the three bestselling passenger cars in the United States. Sales data for 2003 indicated market shares among the top three as follows: Toyota Camry 37%, Honda Accord 34%, and Ford Taurus 29% (The World Almanac, 2004). Assume a sample of 1200 sales of passenger cars during the first quarter of 2004 shows the following.
Passenger Car Units Sold
Toyota Camry .........480
Honda Accord ........390
Ford Taurus ..........330
Can these data be used to conclude that the market shares among the top three passenger cars have changed during the first quarter of 2004? What is the p-value? Use a .05 level of significance. What is your conclusion?