Finding the Third Proportional to 784.69 and 1,210.78

Step by Step Solution

1. Step 1: Write the proportion equation
   784.69 : 1,210.78 = 1,210.78 : x
2. Step 2: Convert to fraction form
   784.69/1,210.78 = 1,210.78/x
3. Step 3: Cross multiply
   784.69x = 1,210.78 × 1,210.78
4. Step 4: Simplify right side
   784.69x = 1,465,991.24
5. Step 5: Solve for x
   x = 1,465,991.24/784.69
6. Step 6: Final answer
   x = 1,868.25