Finding the Fourth Proportional to 39,885.34, 55,042.14 and 21,981

Step by Step Solution

1. Step 1: Write the proportion equation
   39,885.34 : 55,042.14 = 21,981 : x
2. Step 2: Convert to fraction form
   39,885.34/55,042.14 = 21,981/x
3. Step 3: Cross multiply
   39,885.34x = 55,042.14 × 21,981
4. Step 4: Simplify right side
   39,885.34x = 1,209,881,279.34
5. Step 5: Solve for x
   x = 1,209,881,279.34/39,885.34
6. Step 6: Final answer
   x = 30,333.98