Problem 6 (Hypothetical study, inspired by Lee Salk, 1973) A researcher conducted a study to see if the sound of a human heart beat has any effect on newborns weight change during the first few days of their lives. In a big hospital in New York, the researcher randomly assign each of 91 newborns either to a nursery where the continuous sound of a heartbeat played or the other nursery with no sounds. Below is the data of baby's weight gain (in grams) from the day after birth to the fourth day after birth. wg h is weight gains of infants exposed to the heart beat sound and wg n is weight gains of those not exposed to the sound. Use the following R commands to import data into R. Answer questions from (*) - (*) wg