Finding the Fourth Proportional to 31,097.60, 42,880.79 and 21,008.52

Step by Step Solution

1. Step 1: Write the proportion equation
   31,097.60 : 42,880.79 = 21,008.52 : x
2. Step 2: Convert to fraction form
   31,097.60/42,880.79 = 21,008.52/x
3. Step 3: Cross multiply
   31,097.60x = 42,880.79 × 21,008.52
4. Step 4: Simplify right side
   31,097.60x = 900,861,829.29
5. Step 5: Solve for x
   x = 900,861,829.29/31,097.60
6. Step 6: Final answer
   x = 28,968.86