Finding the Fourth Proportional to 39,878.17, 55,031.16 and 21,974.83

Step by Step Solution

1. Step 1: Write the proportion equation
   39,878.17 : 55,031.16 = 21,974.83 : x
2. Step 2: Convert to fraction form
   39,878.17/55,031.16 = 21,974.83/x
3. Step 3: Cross multiply
   39,878.17x = 55,031.16 × 21,974.83
4. Step 4: Simplify right side
   39,878.17x = 1,209,300,385.70
5. Step 5: Solve for x
   x = 1,209,300,385.70/39,878.17
6. Step 6: Final answer
   x = 30,324.87