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**cspan1986** 2. Find the amount accumulated after investing a principal P for t years at an interest rate r. (use r as a decimal-not a %)

P=1,000 t=7 r=9% compounded annually (k=1)

A) $1677.10

B) $1992.56

C) $828.04

D) $1828.04

3. Find the amount accumulated after investing a principal P for t years at an interest rate r. (use r as a decimal-not a %)

P=840 t=5 r=1% compounded continuously

A) $1025.98

B) $124,667.05

C) $1274.19

D) $883.07

4. Suppose the amount of a radioactive element remaining in a sample of 100 milligrams after x years can be described by A(x)=100e^-0.01123x. How much is remaining after 103 years? Round the answer to the nearest hundredth of a milligram.

A) 115.67 mg

B) 0.31 mg

C) 31.45 mg

D) 317.94 mg