The producers of a web game note that there are currently $398$ thousand daily active users, and that number

is falling at an instantaneous rate of approximately $9$ thousand per day.

$($a$)*$ Fill Blank: Use linear approximation to

estimate how many daily active users were in

the game three days earlier.

Users:

$($b$)-$ Multiple Choice: If the rate of change in daily active users was increasing, our approximation in

part $($a$)$ is

the true number of users.

i$.$ an overestimate of

ii$.$ an underestimate of

iii. exactly equal to