Finding the Fourth Proportional to 21,139,886.91, 29,172,547.76 and 12,438,623.10

Step by Step Solution

1. Step 1: Write the proportion equation
   21,139,886.91 : 29,172,547.76 = 12,438,623.10 : x
2. Step 2: Convert to fraction form
   21,139,886.91/29,172,547.76 = 12,438,623.10/x
3. Step 3: Cross multiply
   21,139,886.91x = 29,172,547.76 × 12,438,623.10
4. Step 4: Simplify right side
   21,139,886.91x = 362,866,326,391,196.12
5. Step 5: Solve for x
   x = 362,866,326,391,196.12/21,139,886.91
6. Step 6: Final answer
   x = 17,165,007.93