The first quartile of a data set is 2.5. which statement about the data values is true? a) three-fourths of the values are less than or equal to 2.5, and one-fourth of the values are greater than or equal to 2.5. b) half of the values are less than or equal to 2.5, and half of the values are greater than or equal to 2.5. c) one-fourth of the values are less than or equal to 2.5, and half of the values are greater than or equal to 2.5. d) one-fourth of the values are less than or equal to 2.5, and three-fourths of the values are greater than or equal to 2.5.