According to a Gallup Poll taken in March 2017, 672 Americans in a random sample of 1,018 adult Americans say they have bought a product because it is better for the environment. Part 1 of 3 Calculate the mean and standard deviation, as percentages, of the sampling distribution of this sample proportion (p̂ ) if many samples of size 1,018 are taken. (Round your answers to two decimal places.)