Finding the Fourth Proportional to 12,478,617.60, 18,724,147.20 and 7,091,404.80

Step by Step Solution

1. Step 1: Write the proportion equation
   12,478,617.60 : 18,724,147.20 = 7,091,404.80 : x
2. Step 2: Convert to fraction form
   12,478,617.60/18,724,147.20 = 7,091,404.80/x
3. Step 3: Cross multiply
   12,478,617.60x = 18,724,147.20 × 7,091,404.80
4. Step 4: Simplify right side
   12,478,617.60x = 132,780,507,329,986.55
5. Step 5: Solve for x
   x = 132,780,507,329,986.55/12,478,617.60
6. Step 6: Final answer
   x = 10,640,642.38