Finding the Fourth Proportional to 19,051.72, 26,300.49 and 12,688.90

Step by Step Solution

1. Step 1: Write the proportion equation
   19,051.72 : 26,300.49 = 12,688.90 : x
2. Step 2: Convert to fraction form
   19,051.72/26,300.49 = 12,688.90/x
3. Step 3: Cross multiply
   19,051.72x = 26,300.49 × 12,688.90
4. Step 4: Simplify right side
   19,051.72x = 333,724,287.56
5. Step 5: Solve for x
   x = 333,724,287.56/19,051.72
6. Step 6: Final answer
   x = 17,516.75