Finding the Third Proportional to 531.81 and 782.31

Step by Step Solution

1. Step 1: Write the proportion equation
   531.81 : 782.31 = 782.31 : x
2. Step 2: Convert to fraction form
   531.81/782.31 = 782.31/x
3. Step 3: Cross multiply
   531.81x = 782.31 × 782.31
4. Step 4: Simplify right side
   531.81x = 612,012.85
5. Step 5: Solve for x
   x = 612,012.85/531.81
6. Step 6: Final answer
   x = 1,150.81