Finding the Fourth Proportional to 1,031.50, 1,423.50 and 565.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,031.50 : 1,423.50 = 565.78 : x
2. Step 2: Convert to fraction form
   1,031.50/1,423.50 = 565.78/x
3. Step 3: Cross multiply
   1,031.50x = 1,423.50 × 565.78
4. Step 4: Simplify right side
   1,031.50x = 805,387.83
5. Step 5: Solve for x
   x = 805,387.83/1,031.50
6. Step 6: Final answer
   x = 780.79