Finding the Fourth Proportional to 31,066.64, 42,842.16 and 20,880.72

Step by Step Solution

1. Step 1: Write the proportion equation
   31,066.64 : 42,842.16 = 20,880.72 : x
2. Step 2: Convert to fraction form
   31,066.64/42,842.16 = 20,880.72/x
3. Step 3: Cross multiply
   31,066.64x = 42,842.16 × 20,880.72
4. Step 4: Simplify right side
   31,066.64x = 894,575,147.16
5. Step 5: Solve for x
   x = 894,575,147.16/31,066.64
6. Step 6: Final answer
   x = 28,795.36