Answer:
The answer to your question is 21.9 mi
Step-by-step explanation:
Data
1st day = 3 mi
2nd day = 3.3 mi
3rd day = 3.9 mi
4rd day = 5.1 mi
7fh day = ?
Process
1.- Calculate the pattern
Day 1 2 3 4 5 6 7
MIles 3 3.3 3.9 5.1 7.5 12.3 21.9
Gradient 0.3 0.6 1.2 2.4 4.8 9.6
We notice that the gradient is duplicating so the miles that I bike the seventh day are 21.9.