Pricing Mustangs. According to the Kelley Blue Book, the fair purchase price from dealers for a 2-year-old Ford Mustang coupe is about $18,000. A random sample of 10 purchase prices from private parties yielded the following data, in dollars.

16,594 16,106 16,102 15,914 15,713 15,613 14,614 13,514 15,614 15,714 At the 1% significance level, do the data provide sufficient evidence to conclude that the mean purchase price from private parties for 2-year-old Ford Mustang coupes is less than the fair purchase price from dealers?