Finding the Fourth Proportional to 12,678.63, 19,005.18 and 5,287.17

Step by Step Solution

1. Step 1: Write the proportion equation
   12,678.63 : 19,005.18 = 5,287.17 : x
2. Step 2: Convert to fraction form
   12,678.63/19,005.18 = 5,287.17/x
3. Step 3: Cross multiply
   12,678.63x = 19,005.18 × 5,287.17
4. Step 4: Simplify right side
   12,678.63x = 100,483,617.54
5. Step 5: Solve for x
   x = 100,483,617.54/12,678.63
6. Step 6: Final answer
   x = 7,925.43