I faced the following problem but I do not know how to solve it. Please help me. Thanks.
Let $R$ is a Noetherian graded ring and $I$ is an ideal of $R$, $I^*$ be the ideal generated by all the homogeneous element contained in $I$. Prove that $\operatorname{ht}(I)-1\le\operatorname{ht}(I^{*})\le\operatorname{ht}(I)$.