Finding the Fourth Proportional to 2,013.57, 3,019.76 and 780.70

Step by Step Solution

1. Step 1: Write the proportion equation
   2,013.57 : 3,019.76 = 780.70 : x
2. Step 2: Convert to fraction form
   2,013.57/3,019.76 = 780.70/x
3. Step 3: Cross multiply
   2,013.57x = 3,019.76 × 780.70
4. Step 4: Simplify right side
   2,013.57x = 2,357,526.63
5. Step 5: Solve for x
   x = 2,357,526.63/2,013.57
6. Step 6: Final answer
   x = 1,170.82