Finding the Fourth Proportional to 1,405.72, 1,939.98 and 784.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,405.72 : 1,939.98 = 784.72 : x
2. Step 2: Convert to fraction form
   1,405.72/1,939.98 = 784.72/x
3. Step 3: Cross multiply
   1,405.72x = 1,939.98 × 784.72
4. Step 4: Simplify right side
   1,405.72x = 1,522,341.11
5. Step 5: Solve for x
   x = 1,522,341.11/1,405.72
6. Step 6: Final answer
   x = 1,082.96