Finding the Third Proportional to 142,782 and 310,978

Step by Step Solution

1. Step 1: Write the proportion equation
   142,782 : 310,978 = 310,978 : x
2. Step 2: Convert to fraction form
   142,782/310,978 = 310,978/x
3. Step 3: Cross multiply
   142,782x = 310,978 × 310,978
4. Step 4: Simplify right side
   142,782x = 96,707,316,484
5. Step 5: Solve for x
   x = 96,707,316,484/142,782
6. Step 6: Final answer
   x = 677,307.48