Finding the Fourth Proportional to 13,863, 19,128.72 and 7,812.51

Step by Step Solution

1. Step 1: Write the proportion equation
   13,863 : 19,128.72 = 7,812.51 : x
2. Step 2: Convert to fraction form
   13,863/19,128.72 = 7,812.51/x
3. Step 3: Cross multiply
   13,863x = 19,128.72 × 7,812.51
4. Step 4: Simplify right side
   13,863x = 149,443,316.29
5. Step 5: Solve for x
   x = 149,443,316.29/13,863
6. Step 6: Final answer
   x = 10,780.01