Finding the Fourth Proportional to 13,146.72, 19,728.54 and 5,247.90

Step by Step Solution

1. Step 1: Write the proportion equation
   13,146.72 : 19,728.54 = 5,247.90 : x
2. Step 2: Convert to fraction form
   13,146.72/19,728.54 = 5,247.90/x
3. Step 3: Cross multiply
   13,146.72x = 19,728.54 × 5,247.90
4. Step 4: Simplify right side
   13,146.72x = 103,533,405.07
5. Step 5: Solve for x
   x = 103,533,405.07/13,146.72
6. Step 6: Final answer
   x = 7,875.23