Finding the Fourth Proportional to 1,289.31, 1,933.94 and 315.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,289.31 : 1,933.94 = 315.42 : x
2. Step 2: Convert to fraction form
   1,289.31/1,933.94 = 315.42/x
3. Step 3: Cross multiply
   1,289.31x = 1,933.94 × 315.42
4. Step 4: Simplify right side
   1,289.31x = 610,003.35
5. Step 5: Solve for x
   x = 610,003.35/1,289.31
6. Step 6: Final answer
   x = 473.12