An exponential model can be described by the function

where: a is the initial population or the starting number, b is the base and x is the number of periods elapsed.
When the base of an exponential model is greater than 1 it is called a growth factor, but when it is less than 1 it is called a decay factor.
Given the exponential model

n is the final output of the exponential model, 20.5 is the starting number, 0.6394 is the base and t is the number of periods/time elapsed.
Here, the base is 0.6394 which is less than 1, hence a decay factor.
Therefore, <span>the
base, b, of the exponential model is 0.6394; It is a
decay factor.</span>
You would shift one unit left and one unit up using the formula y=mx+b the b is the y coordinate and the number added or subtracted from the x is the coordinate
well, if look at the timetable, She got the 08:30am train from Aberystwyth and arrives on time at Shrewsbury, from the timetable we know she arrived at 10:17am, now she did some rigamarole and got back to the Train station at Shrewsbury 4 hours later. Well, we know she arrived at 10:17am, if we add 4 hours to that that'll make it 1417 or namely 2:17pm.
well, the Train arrives at Shrewsbury a 14 19, or 2:19pm, she is there at 2:17pm, so she's really 2 minutes before the Train arrives at Shrewsbury, she's right on time, possibly with some munchies too.
14 19 > 14 17.