Final answer:
To find the nth term of an arithmetic sequence, we need to determine the common difference and use the formula nth term = first term + (n - 1) * common difference. Without the first term, we cannot determine the exact value of the nth term.
Step-by-step explanation:
To find the nth term of an arithmetic sequence, we need to determine the common difference, which is the difference between consecutive terms in the sequence. In this case, we can subtract the third term (11.4) from the fifth term (7.8) to find the common difference:
Common difference = 7.8 - 11.4 = -3.6
Now that we have the common difference, we can use the formula for the nth term of an arithmetic sequence:
nth term = first term + (n - 1) * common difference
The first term is not given in the question, so we cannot determine the exact value of the nth term without that information.