Final answer:
In the geometric sequence given, where each term is double the previous one, the fourth term is 8, and the fifth term is 16.
Step-by-step explanation:
The student is asking for the fourth and fifth terms of a sequence where the first three terms are 1, 2, 4. This sequence could be an arithmetic or a geometric sequence. To determine the pattern, we need to look at the differences or ratios between terms. We note that each term doubles the previous term (2 × 1 = 2, 2 × 2 = 4), indicating that it's a geometric sequence with a common ratio r of 2.
- To find the fourth term, we multiply the third term (which is 4) by the common ratio: 4 × 2 = 8.
- Similarly, for the fifth term, we multiply the fourth term by the common ratio: 8 × 2 = 16.
Therefore, the fourth and fifth terms of the sequence are 8 and 16, respectively.