Finding the Third Proportional to 390,126 and 612,145.50

Step by Step Solution

1. Step 1: Write the proportion equation
   390,126 : 612,145.50 = 612,145.50 : x
2. Step 2: Convert to fraction form
   390,126/612,145.50 = 612,145.50/x
3. Step 3: Cross multiply
   390,126x = 612,145.50 × 612,145.50
4. Step 4: Simplify right side
   390,126x = 374,722,113,170.25
5. Step 5: Solve for x
   x = 374,722,113,170.25/390,126
6. Step 6: Final answer
   x = 960,515.61