For this case, the first thing you should know is:
x: number of years after 1950
f (x): amount of vinyl sold.
We have then that the functions evaluated for the number of years are given by:
68594 vinyl records were sold in 1958 ---------> f(8) = 68594
91299 vinyl records were sold in 1961 ---------> f(11) = 91299
38720 vinyl records were sold in 1952 ---------> f(2) = 38720
161743 vinyl records were sold in 1967 ---------> f(17) = 161743
