Explanation:

To find the fifth term of the sequence:

- The average of five terms is given as 15.

- Total of all five terms is \( 5 \times 15 = 75 \).

Given terms:

- First term: 12

- Second term: 17

- Third term: 23

- Fourth term: 8

Calculate the sum of the first four terms:

- Sum = \( 12 + 17 + 23 + 8 = 60 \)

Determine the fifth term:

- Total sum of 5 terms = 75

- Fifth term = Total sum - Sum of first four terms

- Fifth term = \( 75 - 60 = 15 \)

Options:

1. Option: 1 - 30

- Incorrect, as we calculated the fifth term as 15.

2. Option: 2 - 20

- Incorrect, as we calculated the fifth term as 15.

3. Option: 3 - 22

- Incorrect, as we calculated the fifth term as 15.

4. Option: 4 - 15

- Correct, matches our calculation.

Correct answer is Option: 4 - 15.

""