Minimizing tractor skidding distance. Refer to the Journal of Forest Engineering (July 1999) study of minimizing tractor skidding distances along a new road in a European forest, presented in Exercise 7.48 (p. 364). The skidding distances (in meters) were measured at 20 randomly selected road sites. The data are repeated in the accompanying table. Recall that a logger working on the road claims that the mean skidding distance is at least 425 meters. Is there sufficient evidence to refute this claim?

Use a = .10.

488 350 457 199 285 409 435 574 439 546 LO9 385 295 184 261 273 400 311 312 141 425