Exponential Growth in Email Recipients

The video tutorial explains how to model the growth of a chain letter's recipients over time. Derek initially sends the letter to 40 friends, and the number of recipients increases by 90% every three weeks. The growth can be modeled using an exponential function, P(t) = 40 * 1.9^(t/3), where t is the time in weeks. The tutorial walks through the process of setting up the function, calculating growth at different time intervals, and understanding the exponential nature of the problem.

What was the initial number of friends Derek sent the chain letter to?

• 40

• 50

• 30

• 60

How often does the group of email recipients grow by 90%?

• Every 3 weeks

• Every 2 weeks

• Every week

• Every 4 weeks

After 3 weeks, how many people have received the email if it grows by 90%?

• 70

• 72

• 80

• 76

What is the common ratio used in the exponential growth model?

• 1.9

• 2.0

• 1.8

• 2.1

How is the growth of the email recipients described mathematically?

• Quadratic function

• Logarithmic function

• Linear function

• Exponential function

What is the formula for the number of recipients after 6 weeks?

• 40 * 1.9

• 40 * 1.9^2

• 40 * 1.9^3

• 40 * 1.9^4

What does T divided by 3 represent in the growth function?

• Number of days

• Number of months

• Number of 3-week periods

• Number of weeks

What is the initial value in the exponential growth function?

• 40

• 30

• 50

• 60

How does the function P(T) change every 3 weeks?

• It doubles

• It triples

• It grows by 90%

• It decreases by 10%

What is the purpose of dividing T by 3 in the function?

• To find the number of days

• To find the number of 3-week periods

• To find the number of months

• To find the number of years