Finding the Fourth Proportional to 28,442.35, 42,665.69 and 21,788.47

Step by Step Solution

1. Step 1: Write the proportion equation
   28,442.35 : 42,665.69 = 21,788.47 : x
2. Step 2: Convert to fraction form
   28,442.35/42,665.69 = 21,788.47/x
3. Step 3: Cross multiply
   28,442.35x = 42,665.69 × 21,788.47
4. Step 4: Simplify right side
   28,442.35x = 929,619,997.65
5. Step 5: Solve for x
   x = 929,619,997.65/28,442.35
6. Step 6: Final answer
   x = 32,684.36