The germination rate of seeds is defined as the proportion of seeds that sprout and grow when properly planted and watered. A certain variety of grass seed usually has a germination rate of 0.80. A company wants to see if spraying the seeds with a chemical that is known to increase germination rates in other species will increase the germination rate of this variety of grass. The company researchers spray a random sample of 400 grass seeds with the chemical, and 339 of the seeds germinate. Do these data provide convincing evidence at the α = 0.05 significance level that the chemical is effective for this variety of grass?