Exponential Functions Rate vs. Factor

The population of Cary, NC in the year 2000 was 97,400 people. The population steadily grew by 2.5% each year. Which function relates to the situation? Let Population (P) be a function of time (t)

• P(t)=97400+2.5t

• P(t)=97400(2.5)^t

• P(t)=97400(1.25)^t

• P(t)=97400(1.025)^t

David invests $400 in an account that earns 1.5% compound interest. What equation represents the money he will earn in his account each year?

The iPhone X is valued at $1000 upon purchase. The value is expected to decrease by 14% each year. Which function matches the situation? Let Cost (C) be a function of time (t). SELECT ALL THAT APPLY.

Which of the following exponential functions represents an initial value of 1450 and a decay of 18% for x years?

In March, 2020, before the Covid-19 lockdown, 1,200,000 Texans had applied for unemployment. During the COVID-19 lockdown, the number of people applying for unemployment increased by 4% each month. What exponential function can be used to find the number of people applying for unemployment after x months of COVID-19 lockdown?​ (a)  

Which of the following exponential functions represents an initial value of 1780 and a growth of 18% for x years?​

(a)  

• The initial number of waves is 15.

• The initial number of waves decreases at a rate of 85% each day.

• The initial number of waves increases at a rate of 15% each day.

• The number of waves at the end of one day is 354.

The current population of India (2021) is 1.393 billion people, at an annual rate of increase of 97%. Which exponential function models the population, in billions of people, of India after x number of years?​

(a)  

 A flea medicine breaks down at a rate of 20% per hour.  This is the rate of decay of the medicine. The initial dose is 60 milligrams. Which of the following represent the equation the models the amount of flea medicine left in an animal?

Select all the equations that represent exponential decay.