Create and Interpret Exponential Functions to Solve Problems

The expression 5(2)^t gives the number of leaves in a plant as a function of the number of weeks since it was planted. What does 2 represent in this expression?

• There were initially 2 leaves in the plant.

• The number of leaves is multiplied by 2 each week.

• The plant was planted 2 weeks ago.

The expression 1350(1.05)^t models the average wages, in dollars, in the US as a function of the number of years since 1930. What does 1.05 represent in this expression?

• The average wages in the US were about $1.05 in 1930.

• The averages wages in the US increase by about 5% each year.

• The average wages double every 1.05 years.

The expression 3(1.5)^t models the number of bacteria in a culture as a function of the number of hours since the culture was created. What does 3 represent in this expression?

• There were initially 3 bacteria in the culture.

• The number of bacteria is multiplied by 3 each hour.

• The culture was created 3 hours ago

The expression 5∙1.15^t gives the area, in square meters, damaged by a fire as a function of minutes since the fire was discovered. What does 5 represent in this expression?

• An area of 5 square meters had been damaged by the fire by the time it was discovered.

• The area damaged by the fire is multiplied by 5 each minute.

• It has been 5 minutes since the fire was discovered.

The expression 6.7∙1.45^t models the number of billions of genetic sequence bases available in the public database of the Whole Genome Shotgun project t years since 2002. What does 1.45 represent in this expression?

• There were 1.45 billion bases in the database in 2002.

• The number of bases in the database is multiplied by 1.45 each year.

• It is 1.45 years since 2002

The expression 475∙1.076^t models the average annual per capita health care costs, in dollars, in the US as a function of the number of years since 1970. What does 1.076 represent in this expression?

• The per capita health care costs were about $1.076 in 1970.

• The per capita health care costs increase by about 7.6% each year.

• The per capita health care costs double every 76 years.

The expression 900∙2.25^t gives the price performance, in bits per second per dollar, of wireless devices from a certain company as a function of years since the company began. What does 900 represent in this expression?

• The company's initial price efficiency was 900 bits per second per dollar.

• The price efficiency is multiplied by 900 each year.

• The company will have its maximum price efficiency 900 years after it began.

The equation y = 4∙3^x gives the number of ducks living in Anoop's pond x years after he built it. What does 4 represent in this equation?

• There were 4 ducks living in Anoop's pond when he first built it.

• The number of ducks living in Anoop's pond is multiplied by 4 every year.

• It has been 4 years since Anoop built the pond.

The equation C(t) = 11(1.022)^t models the per capita gross domestic product (GDP) of the US, in thousands of dollars, as a function of the number of years since 1950. What does 1.022 represent in this equation?

• The per capita GDP in the US was $1022 in 1950.

• The per capita GDP in the US is multiplied by approximately 1.022 each year.

• The maximum per capita GDP occurred 1.022 years after 1950.

The equation C(t) = 1.5⋅1.09^t models the housing costs, in thousands of dollars, for summer term t years since Chinedu applied to his college. What does 1.09 represent in this equation?

• The summer housing costs were $1,090 the year that Chinedu applied to his college.

• The summer housing costs increase by 9% each year.

• Chinedu applied to his school 9 years ago.