Finding the Fourth Proportional to 1,405.33, 1,939.34 and 816.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,405.33 : 1,939.34 = 816.20 : x
2. Step 2: Convert to fraction form
   1,405.33/1,939.34 = 816.20/x
3. Step 3: Cross multiply
   1,405.33x = 1,939.34 × 816.20
4. Step 4: Simplify right side
   1,405.33x = 1,582,889.31
5. Step 5: Solve for x
   x = 1,582,889.31/1,405.33
6. Step 6: Final answer
   x = 1,126.35