Finding the Fourth Proportional to 12,991.18, 19,485.15 and 5,200.06

Step by Step Solution

1. Step 1: Write the proportion equation
   12,991.18 : 19,485.15 = 5,200.06 : x
2. Step 2: Convert to fraction form
   12,991.18/19,485.15 = 5,200.06/x
3. Step 3: Cross multiply
   12,991.18x = 19,485.15 × 5,200.06
4. Step 4: Simplify right side
   12,991.18x = 101,323,949.11
5. Step 5: Solve for x
   x = 101,323,949.11/12,991.18
6. Step 6: Final answer
   x = 7,799.44