Finding the Fourth Proportional to 21,333.63, 31,930.73 and 19,287.42

Step by Step Solution

1. Step 1: Write the proportion equation
   21,333.63 : 31,930.73 = 19,287.42 : x
2. Step 2: Convert to fraction form
   21,333.63/31,930.73 = 19,287.42/x
3. Step 3: Cross multiply
   21,333.63x = 31,930.73 × 19,287.42
4. Step 4: Simplify right side
   21,333.63x = 615,861,400.42
5. Step 5: Solve for x
   x = 615,861,400.42/21,333.63
6. Step 6: Final answer
   x = 28,868.10