Finding the Third Proportional to 252,588 and 390,140

Step by Step Solution

1. Step 1: Write the proportion equation
   252,588 : 390,140 = 390,140 : x
2. Step 2: Convert to fraction form
   252,588/390,140 = 390,140/x
3. Step 3: Cross multiply
   252,588x = 390,140 × 390,140
4. Step 4: Simplify right side
   252,588x = 152,209,219,600
5. Step 5: Solve for x
   x = 152,209,219,600/252,588
6. Step 6: Final answer
   x = 602,598.78