Finding the Fourth Proportional to 1,429.20, 2,141.82 and 780.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,429.20 : 2,141.82 = 780.48 : x
2. Step 2: Convert to fraction form
   1,429.20/2,141.82 = 780.48/x
3. Step 3: Cross multiply
   1,429.20x = 2,141.82 × 780.48
4. Step 4: Simplify right side
   1,429.20x = 1,671,647.67
5. Step 5: Solve for x
   x = 1,671,647.67/1,429.20
6. Step 6: Final answer
   x = 1,169.64