In this case, we'll have to carry out several steps to find the solution.
Step 01:
data:
t1 = 800
tn = - 0.25 tn-1
Step 02:
sequence:
t1 = 800
t2 = -0.25 (800) = - 200
t3 = -0.25 (-200) = 50
t4 = -0.25 (50) = -12.5
t5 = - 0.25 (-12.5) = 3.125
The answer is:
t1 = 800
t2 = - 200
t3 = 50
t4 = -12.5
t5 = 3.125