Finding the Fourth Proportional to 61,242.55, 91,872.20 and 21,790.15

Step by Step Solution

1. Step 1: Write the proportion equation
   61,242.55 : 91,872.20 = 21,790.15 : x
2. Step 2: Convert to fraction form
   61,242.55/91,872.20 = 21,790.15/x
3. Step 3: Cross multiply
   61,242.55x = 91,872.20 × 21,790.15
4. Step 4: Simplify right side
   61,242.55x = 2,001,909,018.83
5. Step 5: Solve for x
   x = 2,001,909,018.83/61,242.55
6. Step 6: Final answer
   x = 32,688.20