Finding the Fourth Proportional to 1,646.50, 2,470.83 and 780.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,646.50 : 2,470.83 = 780.88 : x
2. Step 2: Convert to fraction form
   1,646.50/2,470.83 = 780.88/x
3. Step 3: Cross multiply
   1,646.50x = 2,470.83 × 780.88
4. Step 4: Simplify right side
   1,646.50x = 1,929,421.73
5. Step 5: Solve for x
   x = 1,929,421.73/1,646.50
6. Step 6: Final answer
   x = 1,171.83