Finding the Third Proportional to 142,985 and 313,978

Step by Step Solution

1. Step 1: Write the proportion equation
   142,985 : 313,978 = 313,978 : x
2. Step 2: Convert to fraction form
   142,985/313,978 = 313,978/x
3. Step 3: Cross multiply
   142,985x = 313,978 × 313,978
4. Step 4: Simplify right side
   142,985x = 98,582,184,484
5. Step 5: Solve for x
   x = 98,582,184,484/142,985
6. Step 6: Final answer
   x = 689,458.23