Finding the Fourth Proportional to 56,688.83, 85,030.43 and 21,147.36

Step by Step Solution

1. Step 1: Write the proportion equation
   56,688.83 : 85,030.43 = 21,147.36 : x
2. Step 2: Convert to fraction form
   56,688.83/85,030.43 = 21,147.36/x
3. Step 3: Cross multiply
   56,688.83x = 85,030.43 × 21,147.36
4. Step 4: Simplify right side
   56,688.83x = 1,798,169,008.43
5. Step 5: Solve for x
   x = 1,798,169,008.43/56,688.83
6. Step 6: Final answer
   x = 31,719.99