Finding the Fourth Proportional to 30,978.34, 42,756.33 and 18,400.66

Step by Step Solution

1. Step 1: Write the proportion equation
   30,978.34 : 42,756.33 = 18,400.66 : x
2. Step 2: Convert to fraction form
   30,978.34/42,756.33 = 18,400.66/x
3. Step 3: Cross multiply
   30,978.34x = 42,756.33 × 18,400.66
4. Step 4: Simplify right side
   30,978.34x = 786,744,691.18
5. Step 5: Solve for x
   x = 786,744,691.18/30,978.34
6. Step 6: Final answer
   x = 25,396.61