Finding the Fourth Proportional to 21,130.01, 31,631.88 and 12,784.81

Step by Step Solution

1. Step 1: Write the proportion equation
   21,130.01 : 31,631.88 = 12,784.81 : x
2. Step 2: Convert to fraction form
   21,130.01/31,631.88 = 12,784.81/x
3. Step 3: Cross multiply
   21,130.01x = 31,631.88 × 12,784.81
4. Step 4: Simplify right side
   21,130.01x = 404,407,417.58
5. Step 5: Solve for x
   x = 404,407,417.58/21,130.01
6. Step 6: Final answer
   x = 19,139.01