Finding the Fourth Proportional to 2,339.78, 3,510.28 and 780.02

Step by Step Solution

1. Step 1: Write the proportion equation
   2,339.78 : 3,510.28 = 780.02 : x
2. Step 2: Convert to fraction form
   2,339.78/3,510.28 = 780.02/x
3. Step 3: Cross multiply
   2,339.78x = 3,510.28 × 780.02
4. Step 4: Simplify right side
   2,339.78x = 2,738,088.61
5. Step 5: Solve for x
   x = 2,738,088.61/2,339.78
6. Step 6: Final answer
   x = 1,170.23