Finding the Fourth Proportional to 1,520.46, 2,279.58 and 780.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,520.46 : 2,279.58 = 780.30 : x
2. Step 2: Convert to fraction form
   1,520.46/2,279.58 = 780.30/x
3. Step 3: Cross multiply
   1,520.46x = 2,279.58 × 780.30
4. Step 4: Simplify right side
   1,520.46x = 1,778,756.27
5. Step 5: Solve for x
   x = 1,778,756.27/1,520.46
6. Step 6: Final answer
   x = 1,169.88