Finding the Fourth Proportional to 85,379,408.53, 128,120,118.59 and 78,433,017.78

Step by Step Solution

1. Step 1: Write the proportion equation
   85,379,408.53 : 128,120,118.59 = 78,433,017.78 : x
2. Step 2: Convert to fraction form
   85,379,408.53/128,120,118.59 = 78,433,017.78/x
3. Step 3: Cross multiply
   85,379,408.53x = 128,120,118.59 × 78,433,017.78
4. Step 4: Simplify right side
   85,379,408.53x = 10,048,847,539,345,178
5. Step 5: Solve for x
   x = 10,048,847,539,345,178/85,379,408.53
6. Step 6: Final answer
   x = 117,696,382.68