Finding the Fourth Proportional to 31,096.09, 42,878.72 and 21,007.02

Step by Step Solution

1. Step 1: Write the proportion equation
   31,096.09 : 42,878.72 = 21,007.02 : x
2. Step 2: Convert to fraction form
   31,096.09/42,878.72 = 21,007.02/x
3. Step 3: Cross multiply
   31,096.09x = 42,878.72 × 21,007.02
4. Step 4: Simplify right side
   31,096.09x = 900,754,181.13
5. Step 5: Solve for x
   x = 900,754,181.13/31,096.09
6. Step 6: Final answer
   x = 28,966.80