Finding the Third Proportional to 142,531.50 and 309,870.75

Step by Step Solution

1. Step 1: Write the proportion equation
   142,531.50 : 309,870.75 = 309,870.75 : x
2. Step 2: Convert to fraction form
   142,531.50/309,870.75 = 309,870.75/x
3. Step 3: Cross multiply
   142,531.50x = 309,870.75 × 309,870.75
4. Step 4: Simplify right side
   142,531.50x = 96,019,881,705.56
5. Step 5: Solve for x
   x = 96,019,881,705.56/142,531.50
6. Step 6: Final answer
   x = 673,674.81