Let ∑an be a series and let \(\mathop {\lim }\limits_{n \to \infty } \frac{{{a_{k + 1}}}}{{{a_k}}} = L\), then which of the following statements does not express the condition for the ratio test?
1
If L < 1, then the series converges
2
If L > 1, then the series diverges
3
If L = 0, then the series neither converges nor diverges
4
If L = 1, then the test fails and is inconclusive