Exponential Functions (growth/decay, geometric sequences)

The value of a sculpture is increasing 5% every month. The original value of the sculpture is $6,400. Identify the exponential growth function to model this situation.

• y = 6400(1.5)^t
• y = 6400(1.05)^t
• y = 6400(0.95)^t
• y = 6400(15)^t

$20,000 is invested at a rate of 5% compounded quarterly. Find the balance after 5 years. 

• $20,460.81
• $20,106.73
• $25,601.69
• $25,640.74

$2,000 is invested at a rate of 4.2% compounded annually. Find the balance after 7 years. 

• $2,667.50
• $2,557.50
• $2,337.50
• $2,447.50

The population of an endangered species of insect is 480,000. The population decreases at the rate of 10% per year. Find the population of the species after 3 years. 

• 280,000
• 638,880
• 339,940
• 349,920

Cesium-137 has a half-life of 30 years. Identify the amount of cesium-137 left from 150 milligram sample after 120 years. 

• 0.9375 mg
• 9.3750 mg
• 1.097 mg
• 1.325 mg

Identify the next three terms in the geometric sequence. 
8, 24, 72, 216, ...

• 512, 1024, 4832
• 648, 1944, 3888
• 512, 1536, 4608
• 648, 1944, 5832

Identify the next three terms in the geometric sequence. 
1, -1/3, 1/9, -1/27,...

• -1/81, 1/243, -1/729
• 1/81, -1/243, 1/729
• -1/54, 1/81, -1/243
• 1/54, -1/162, 1/486

The first term of a geometric sequence is 400 and the common ratio is 0.5. What is the 5^th term of the sequence?

• 100
• 50
• 25
• 5

The 12th term of the sequence is
3, -9, 27, -81, 243,...?

• 531,441
• 177,147
• -177,147
• -531,441

The table shows the value of a townhome for 3 years after it is purchased. The values form a geometric sequence. If the pattern continues, how much will the townhome be worth after 7 years?

• $457,763.67
• $457,633.12
• $452,000.00
• $366,210.93