L Attempt in Progress Let f(t) be the number of people, in millions, who own cell phones t years after 1990. Explain the meaning of the following statements. (a) f(10) = 101.7 The number of people who own cell phones in the year is i million. (b) f(a) = 20 million people own cell phones years after 1990. (c) f(20) = b million people own cell phones in the year (d) f(t) = n million people own cell phones years after 1990