Finding the Third Proportional to 166,300 and 390,440

Step by Step Solution

1. Step 1: Write the proportion equation
   166,300 : 390,440 = 390,440 : x
2. Step 2: Convert to fraction form
   166,300/390,440 = 390,440/x
3. Step 3: Cross multiply
   166,300x = 390,440 × 390,440
4. Step 4: Simplify right side
   166,300x = 152,443,393,600
5. Step 5: Solve for x
   x = 152,443,393,600/166,300
6. Step 6: Final answer
   x = 916,677.05