Finding the Fourth Proportional to 85,780.78, 128,528.89 and 60,696.49

Step by Step Solution

1. Step 1: Write the proportion equation
   85,780.78 : 128,528.89 = 60,696.49 : x
2. Step 2: Convert to fraction form
   85,780.78/128,528.89 = 60,696.49/x
3. Step 3: Cross multiply
   85,780.78x = 128,528.89 × 60,696.49
4. Step 4: Simplify right side
   85,780.78x = 7,801,252,486.60
5. Step 5: Solve for x
   x = 7,801,252,486.60/85,780.78
6. Step 6: Final answer
   x = 90,944.06