Finding the Fourth Proportional to 12,992.39, 19,488.55 and 3,131.65

Step by Step Solution

1. Step 1: Write the proportion equation
   12,992.39 : 19,488.55 = 3,131.65 : x
2. Step 2: Convert to fraction form
   12,992.39/19,488.55 = 3,131.65/x
3. Step 3: Cross multiply
   12,992.39x = 19,488.55 × 3,131.65
4. Step 4: Simplify right side
   12,992.39x = 61,031,317.61
5. Step 5: Solve for x
   x = 61,031,317.61/12,992.39
6. Step 6: Final answer
   x = 4,697.47