Finding the Third Proportional to 145,274 and 316,280

Step by Step Solution

1. Step 1: Write the proportion equation
   145,274 : 316,280 = 316,280 : x
2. Step 2: Convert to fraction form
   145,274/316,280 = 316,280/x
3. Step 3: Cross multiply
   145,274x = 316,280 × 316,280
4. Step 4: Simplify right side
   145,274x = 100,033,038,400
5. Step 5: Solve for x
   x = 100,033,038,400/145,274
6. Step 6: Final answer
   x = 688,581.84