Finding the Fourth Proportional to 31,099.84, 42,883.90 and 21,010.76

Step by Step Solution

1. Step 1: Write the proportion equation
   31,099.84 : 42,883.90 = 21,010.76 : x
2. Step 2: Convert to fraction form
   31,099.84/42,883.90 = 21,010.76/x
3. Step 3: Cross multiply
   31,099.84x = 42,883.90 × 21,010.76
4. Step 4: Simplify right side
   31,099.84x = 901,023,330.76
5. Step 5: Solve for x
   x = 901,023,330.76/31,099.84
6. Step 6: Final answer
   x = 28,971.96