Finding the Fourth Proportional to 13,156.88, 18,155.96 and 7,782.80

Step by Step Solution

1. Step 1: Write the proportion equation
   13,156.88 : 18,155.96 = 7,782.80 : x
2. Step 2: Convert to fraction form
   13,156.88/18,155.96 = 7,782.80/x
3. Step 3: Cross multiply
   13,156.88x = 18,155.96 × 7,782.80
4. Step 4: Simplify right side
   13,156.88x = 141,304,075.79
5. Step 5: Solve for x
   x = 141,304,075.79/13,156.88
6. Step 6: Final answer
   x = 10,739.94