Finding the Third Proportional to 221,428.50 and 312,030

Step by Step Solution

1. Step 1: Write the proportion equation
   221,428.50 : 312,030 = 312,030 : x
2. Step 2: Convert to fraction form
   221,428.50/312,030 = 312,030/x
3. Step 3: Cross multiply
   221,428.50x = 312,030 × 312,030
4. Step 4: Simplify right side
   221,428.50x = 97,362,720,900
5. Step 5: Solve for x
   x = 97,362,720,900/221,428.50
6. Step 6: Final answer
   x = 439,702.75