Finding the Third Proportional to 428.20 and 940.78

Step by Step Solution

1. Step 1: Write the proportion equation
   428.20 : 940.78 = 940.78 : x
2. Step 2: Convert to fraction form
   428.20/940.78 = 940.78/x
3. Step 3: Cross multiply
   428.20x = 940.78 × 940.78
4. Step 4: Simplify right side
   428.20x = 885,069.36
5. Step 5: Solve for x
   x = 885,069.36/428.20
6. Step 6: Final answer
   x = 2,066.94