Finding the Fourth Proportional to 42,742.64, 64,126.92 and 20,549.72

Step by Step Solution

1. Step 1: Write the proportion equation
   42,742.64 : 64,126.92 = 20,549.72 : x
2. Step 2: Convert to fraction form
   42,742.64/64,126.92 = 20,549.72/x
3. Step 3: Cross multiply
   42,742.64x = 64,126.92 × 20,549.72
4. Step 4: Simplify right side
   42,742.64x = 1,317,789,929.83
5. Step 5: Solve for x
   x = 1,317,789,929.83/42,742.64
6. Step 6: Final answer
   x = 30,830.81