A builder contracted for the delivery of 4 million pounds of loam. The supplier delivered the loam in 1000 truckloads that he claims average 4000 pounds of loam. The builder weighed a random sample of 16 truckloads and obtained these data:

3820 3900 4000 3820 3780 3880 3700 3620 4380 3560 3840 3980 4040 4140 3780 3780

Using a one-tailed test, do these data reject the supplier's claim at the 5 percent level?