Finding the Fourth Proportional to 85,873.86, 128,769.89 and 31,820.94

Step by Step Solution

1. Step 1: Write the proportion equation
   85,873.86 : 128,769.89 = 31,820.94 : x
2. Step 2: Convert to fraction form
   85,873.86/128,769.89 = 31,820.94/x
3. Step 3: Cross multiply
   85,873.86x = 128,769.89 × 31,820.94
4. Step 4: Simplify right side
   85,873.86x = 4,097,578,784.39
5. Step 5: Solve for x
   x = 4,097,578,784.39/85,873.86
6. Step 6: Final answer
   x = 47,716.25