Finding the Fourth Proportional to 28,245.78, 42,382.59 and 19,978.92

Step by Step Solution

1. Step 1: Write the proportion equation
   28,245.78 : 42,382.59 = 19,978.92 : x
2. Step 2: Convert to fraction form
   28,245.78/42,382.59 = 19,978.92/x
3. Step 3: Cross multiply
   28,245.78x = 42,382.59 × 19,978.92
4. Step 4: Simplify right side
   28,245.78x = 846,758,375.00
5. Step 5: Solve for x
   x = 846,758,375.00/28,245.78
6. Step 6: Final answer
   x = 29,978.23