Finding the Third Proportional to 309.95 and 410.86

Step by Step Solution

1. Step 1: Write the proportion equation
   309.95 : 410.86 = 410.86 : x
2. Step 2: Convert to fraction form
   309.95/410.86 = 410.86/x
3. Step 3: Cross multiply
   309.95x = 410.86 × 410.86
4. Step 4: Simplify right side
   309.95x = 168,808.74
5. Step 5: Solve for x
   x = 168,808.74/309.95
6. Step 6: Final answer
   x = 544.63