Finding the Third Proportional to 190,688 and 258,978

Step by Step Solution

1. Step 1: Write the proportion equation
   190,688 : 258,978 = 258,978 : x
2. Step 2: Convert to fraction form
   190,688/258,978 = 258,978/x
3. Step 3: Cross multiply
   190,688x = 258,978 × 258,978
4. Step 4: Simplify right side
   190,688x = 67,069,604,484
5. Step 5: Solve for x
   x = 67,069,604,484/190,688
6. Step 6: Final answer
   x = 351,724.31