Finding the Fourth Proportional to 21,009.48, 28,986.89 and 12,507.32

Step by Step Solution

1. Step 1: Write the proportion equation
   21,009.48 : 28,986.89 = 12,507.32 : x
2. Step 2: Convert to fraction form
   21,009.48/28,986.89 = 12,507.32/x
3. Step 3: Cross multiply
   21,009.48x = 28,986.89 × 12,507.32
4. Step 4: Simplify right side
   21,009.48x = 362,548,101.56
5. Step 5: Solve for x
   x = 362,548,101.56/21,009.48
6. Step 6: Final answer
   x = 17,256.41