Finding the Fourth Proportional to 30,999.58, 42,779.55 and 18,424.42

Step by Step Solution

1. Step 1: Write the proportion equation
   30,999.58 : 42,779.55 = 18,424.42 : x
2. Step 2: Convert to fraction form
   30,999.58/42,779.55 = 18,424.42/x
3. Step 3: Cross multiply
   30,999.58x = 42,779.55 × 18,424.42
4. Step 4: Simplify right side
   30,999.58x = 788,188,396.61
5. Step 5: Solve for x
   x = 788,188,396.61/30,999.58
6. Step 6: Final answer
   x = 25,425.78