Finding the Fourth Proportional to 1,282.20, 1,769.50 and 784.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,282.20 : 1,769.50 = 784.69 : x
2. Step 2: Convert to fraction form
   1,282.20/1,769.50 = 784.69/x
3. Step 3: Cross multiply
   1,282.20x = 1,769.50 × 784.69
4. Step 4: Simplify right side
   1,282.20x = 1,388,501.10
5. Step 5: Solve for x
   x = 1,388,501.10/1,282.20
6. Step 6: Final answer
   x = 1,082.90