Among people who marry in the US, the mean age at first marriage is 25 years, and the 50th percentile is 27. Therefore: (Choose all that are correct) - a. the median of age at first marriage is more than 25 years b. the distribution of age at first marriage is normal c. the distribution of age at first marriage is skewed to the right (positive tail). d. the distribution of age at first marriage is skewed to the left (negative tail)