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| Question 1058562:  How long will it take for $1300 to grow to $2300 at an interest rate of  6.4% if the interest is compounded quarterly? Round the number of years to the nearest hundredth.
 Select one:
 a. 8.99
 b. 35.94
 c. 27.86
 d. 9.20
 Answer by solve_for_x(190)
      (Show Source): 
You can put this solution on YOUR website! The formula for compound interest is: 
 FV = PV(1 + r/n)^(nt)
 
 where FV is the future value, PV is the present value, r is the annual interest
 rate, n is the number of periods per year, and t is the number of years.
 
 For this problem, FV = 2300, PV = 1300, r = 0.064, and n = 4.
 
 Substituting those values into the equation gives:
 
 2300 = 1300(1 + 0.064/4)^(4t)
 
 2300 = 1300(1.016)^(4t)
 
 (1.016)^(4t) = 2300/1300
 
 Taking the natural logarithm of both sides then gives:
 
 4t * ln(1.016) = ln(2300/1300)
 
 t = ln(2300/1300) / 4*ln(1.016)
 
 t = 8.99 years
 
 Check:
 
 1300(1.016)^(4*8.99) = 1300(1.7697) = 2300.60
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