Answer:
25
Step-by-step explanation:
The n th term of a geometric sequence is
[tex]a_{n}[/tex] = a₁ [tex]r^{n-1}[/tex]
where a₁ is the first term and r the common ratio
Here a₁ = 400 and r = 0.5 , thus
[tex]a_{5}[/tex] = 400 × [tex](0.5)^{4}[/tex] = 400 × 0.0625 = 25
