Finding the Fourth Proportional to 85,810.72, 128,696.64 and 30,406.72

Step by Step Solution

1. Step 1: Write the proportion equation
   85,810.72 : 128,696.64 = 30,406.72 : x
2. Step 2: Convert to fraction form
   85,810.72/128,696.64 = 30,406.72/x
3. Step 3: Cross multiply
   85,810.72x = 128,696.64 × 30,406.72
4. Step 4: Simplify right side
   85,810.72x = 3,913,242,697.42
5. Step 5: Solve for x
   x = 3,913,242,697.42/85,810.72
6. Step 6: Final answer
   x = 45,603.19