Answer:
Explanation:
The number of emails is multiplied by <em>4</em> every <em>9.1 weeks.</em>
Thus, since <em>Tobias initially sent the chain letter to 37 friends</em>, the number of letters will grow as per this geometric series:
Start: 37 letters
- In 9.1 weeks: 37 × 4
- In 2 × 9.1 weeks: 37 × (4)²
- In 3 × 9.1 weeks: 37 × (4)³
As you see, the exponent is the number of weeks divided by 9.1
Thus, if your variable is the number of weeks, t, then the exponent is t/9.1
And the exponential function, P(t) will be: