Final answer:
The null hypothesis may be rejected at the 0.05 level of significance, but not at the 0.20 level of significance.
Step-by-step explanation:
The statement is sometimes not correct.
When the null hypothesis is rejected at the 0.05 level of significance, it means that there is strong evidence to suggest that the null hypothesis is false. However, the decision to reject the null hypothesis depends on the level of significance chosen. If the level of significance is increased to 0.20, it means that the criteria for rejecting the null hypothesis is less strict. Therefore, there is a possibility that the null hypothesis could be rejected at the 0.05 level but not at the 0.20 level.