The position of a particle moving to the right on the x x
-axis is given by x(t)
x
(
t
)
, where x(t)
x
(
t
)
is measured in inches and t
t
is measured in minutes for 0≤t≤100
0
≤
t
≤
100
. If y=x(t)
y
=
x
(
t
)
is a linear function, which of the following would most likely give the best estimate of the speed of the particle, in inches per minute, at time t=20
t
=
20
minutes?