Has the marrying age of a man changed over the years? the united states bureau of the census takes a formal count of everyone in the u. s. every 10 years and has provided the following data that gives the median age of an american man at the time of his first marriage. year 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 median age 25.1 24.6 24.3 24.3 22.8 22.8 23.2 24.7 26.1 26.8 what does a rate of change of zero mean in this situation? a. the median age of a man at the time of his first marriage is, on the average, constant. b. the median age of a man at the time of his first marriage is, on the average, decreasing. c. the median age of a man at the time of his first marriage is, on the average, increasing. d. the rate of change cannot be zero in this situation.