Finding the Third Proportional to 1,428.89 and 2,209.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,428.89 : 2,209.15 = 2,209.15 : x
2. Step 2: Convert to fraction form
   1,428.89/2,209.15 = 2,209.15/x
3. Step 3: Cross multiply
   1,428.89x = 2,209.15 × 2,209.15
4. Step 4: Simplify right side
   1,428.89x = 4,880,336.82
5. Step 5: Solve for x
   x = 4,880,336.82/1,428.89
6. Step 6: Final answer
   x = 3,415.47