Finding the Fourth Proportional to 21,035.76, 31,543.92 and 7,878.72

Step by Step Solution

1. Step 1: Write the proportion equation
   21,035.76 : 31,543.92 = 7,878.72 : x
2. Step 2: Convert to fraction form
   21,035.76/31,543.92 = 7,878.72/x
3. Step 3: Cross multiply
   21,035.76x = 31,543.92 × 7,878.72
4. Step 4: Simplify right side
   21,035.76x = 248,525,713.38
5. Step 5: Solve for x
   x = 248,525,713.38/21,035.76
6. Step 6: Final answer
   x = 11,814.44