Finding the Fourth Proportional to 30,978.70, 42,750.61 and 18,403.45

Step by Step Solution

1. Step 1: Write the proportion equation
   30,978.70 : 42,750.61 = 18,403.45 : x
2. Step 2: Convert to fraction form
   30,978.70/42,750.61 = 18,403.45/x
3. Step 3: Cross multiply
   30,978.70x = 42,750.61 × 18,403.45
4. Step 4: Simplify right side
   30,978.70x = 786,758,852.95
5. Step 5: Solve for x
   x = 786,758,852.95/30,978.70
6. Step 6: Final answer
   x = 25,396.77