A public health organization reports that 25% of baby boys 6 - 8 months old in the United States weigh more than 20 pounds. A sample of 11 babies is studied. (a) What is the mean number who weigh more than 20 pounds in a sample of 11 babies aged 6 - 8 months? Round the answer to two decimal places. The mean number who weigh more than 20 pounds is (b) What is the standard deviation of the number who weigh more than 20 pounds in a sample of 11 babies aged 6-8 months? Round the answer to four decimal places. The standard deviation of the number who weigh more than 20 pounds is