Finding the Fourth Proportional to 31,097.26, 42,880.30 and 21,008.18

Step by Step Solution

1. Step 1: Write the proportion equation
   31,097.26 : 42,880.30 = 21,008.18 : x
2. Step 2: Convert to fraction form
   31,097.26/42,880.30 = 21,008.18/x
3. Step 3: Cross multiply
   31,097.26x = 42,880.30 × 21,008.18
4. Step 4: Simplify right side
   31,097.26x = 900,836,874.33
5. Step 5: Solve for x
   x = 900,836,874.33/31,097.26
6. Step 6: Final answer
   x = 28,968.37