At the start of 2004, an online social group had 0.6 million members. Since that time, new members joined at a rate of approximately
m(t) = 7.5t^2 + 16t − 5 million members per year (0 ≤ t ≤ 3.5)
where t is time in years since the start of 2004.
(a) Find an expression for the total online social group membership M(t) at time t.
(b) Use the answer to part (a) to estimate the group's membership in January 2007. (Round your answer to the nearest million members.)

Question

At the start of 2004, an online social group had 0.6 million members. Since that time, new members joined at a rate of approximately
m(t) = 7.5t^2 + 16t − 5 million members per year    (0 ≤ t ≤ 3.5)
where t is time in years since the start of 2004.
(a) Find an expression for the total online social group membership M(t) at time t.
(b) Use the answer to part (a) to estimate the group's membership in January 2007. (Round your answer to the nearest million members.)