For a given arithmetic sequence, the common difference, $d$, is equal to -7 , and the ${88}^{\text{th }}$ term, $a_{88}$, is equal to -624 . Find the value of the ${38}^{\text{th }}$ term, $a_{38}$.

Step 1 ：Given that the common difference, $d$, is equal to -7, and the ${88}^{th}$ term, $a_{88}$, is equal to -624.

Step 2 ：Using the formula for the nth term of an arithmetic sequence, $a_n=a_1+(n-1)d$, we can substitute the known values to find the first term, $a_1$.

Step 3 ：Substituting $d=-7$ and $a_{88}=-624$ into the formula, we get $-624=a_1+(88-1)(-7)$.

Step 4 ：Solving the equation, we find that $a_1=-15$.

Step 5 ：Now, we can use the same formula to find the ${38}^{th}$ term, $a_{38}$.

Step 6 ：Substituting $a_1=-15$, $d=-7$, and $n=38$ into the formula, we get $a_{38}=-15+(38-1)(-7)$.

Step 7 ：Solving the equation, we find that $a_{38}=-274$.

Step 8 ：Final Answer: The 38th term of the sequence is $\boxed{{\displaystyle -274}}$.