Answer:

Explanation:
This is an exponential growing: there is a constant growing<em> factor </em>which multiplies the value number of letters sent every week.
The growing factor <em>4 letters every 9.1 weeks</em> means that every 9.1 weeks the number of letters is multiplied by 4.
Then, if the number of weeks is t, the number of times the number of letters increase is t/9.1.
Then, the exponential<em> function</em> <em>that models the number of people who receive the email t weeks since Tobias initially sent the chain letter</em>, has the form:

<em>Tobias initially sent the chain letter to 37 friends</em>; thus, the initial value is 37, and the complete function is:
, where t is the number of weeks since Tobias initially sent the chain letter.
B is 12
c is 6 because you don't count the zero
Answer:
-2
Step-by-step explanation:
Since they are parallel, they have the same slope. This will be true for any set of lines.
Answer:
both of the questions are examples of convenience samples
Step-by-step explanation:
A voluntary response would be where the people get to choose to respond to the survey. In both of these cases, teachers are specifically asking for their students opinions.
Whatever% of anything is just (whatever/100) * anything.
let's say we'll add "x" cups of pure vinegar, pure vinegar meaning is 100% vinegar.
how much vinegar is there in "x" cups of 100% vinegar? well (100/100) * x, or just "x".
how much vinegar is there in 10 cups of 10% vinegar? well, (10/100) * 10, or just 1.
say after adding the "x" cups to the 10 cups, we end up with "y" cups, of 50% of vinegar.
how much is 50% of y? well, (50/100) * y or 0.5y.
bearing in mind that x+10 = y, both cups amounts added up, and that x+1=0.5y, both vinegar amounts added up, thus