Finding the Third Proportional to 287,986 and 405,370.50

Step by Step Solution

1. Step 1: Write the proportion equation
   287,986 : 405,370.50 = 405,370.50 : x
2. Step 2: Convert to fraction form
   287,986/405,370.50 = 405,370.50/x
3. Step 3: Cross multiply
   287,986x = 405,370.50 × 405,370.50
4. Step 4: Simplify right side
   287,986x = 164,325,242,270.25
5. Step 5: Solve for x
   x = 164,325,242,270.25/287,986
6. Step 6: Final answer
   x = 570,601.50