Answer:
Explanation:
The number of emails is multiplied by 4 every 9.1 weeks.
Thus, since Tobias initially sent the chain letter to 37 friends, the number of letters will grow as per this geometric series:
Start: 37 letters
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:
[tex]P(t)=37\times (4)^{(t/9.1)}[/tex]