In the four term sequence $0.001,0.02,0.4, x$, each term after the first is found by multiplying the previous term by the same number. What is the value of $x$ ?
(A) 0.8
(B) 8
(C) 80
(D) 8.8
(E) 0.08
To determine the number by which we multiply the third term to obtain the fourth term, we can divide the second term by the first term. Doing this, we get $\frac{0.02}{0.001}=20$.

(We can check that this is also equal to the third term divided by the second term.) Therefore, the fourth term is $20(0.4)=8$.

ANswer: (B)