Finding the Fourth Proportional to 85,698.05, 128,499 and 58,710.89

Step by Step Solution

1. Step 1: Write the proportion equation
   85,698.05 : 128,499 = 58,710.89 : x
2. Step 2: Convert to fraction form
   85,698.05/128,499 = 58,710.89/x
3. Step 3: Cross multiply
   85,698.05x = 128,499 × 58,710.89
4. Step 4: Simplify right side
   85,698.05x = 7,544,290,975.36
5. Step 5: Solve for x
   x = 7,544,290,975.36/85,698.05
6. Step 6: Final answer
   x = 88,033.40