Finding the Third Proportional to 400.31 and 613.31

Step by Step Solution

1. Step 1: Write the proportion equation
   400.31 : 613.31 = 613.31 : x
2. Step 2: Convert to fraction form
   400.31/613.31 = 613.31/x
3. Step 3: Cross multiply
   400.31x = 613.31 × 613.31
4. Step 4: Simplify right side
   400.31x = 376,152.22
5. Step 5: Solve for x
   x = 376,152.22/400.31
6. Step 6: Final answer
   x = 939.65