Finding the Fourth Proportional to 5,280.47, 7,921.89 and 2,160.06

Step by Step Solution

1. Step 1: Write the proportion equation
   5,280.47 : 7,921.89 = 2,160.06 : x
2. Step 2: Convert to fraction form
   5,280.47/7,921.89 = 2,160.06/x
3. Step 3: Cross multiply
   5,280.47x = 7,921.89 × 2,160.06
4. Step 4: Simplify right side
   5,280.47x = 17,111,777.63
5. Step 5: Solve for x
   x = 17,111,777.63/5,280.47
6. Step 6: Final answer
   x = 3,240.58