Finding the Fourth Proportional to 1,347.29, 1,858.61 and 780.09

Step by Step Solution

1. Step 1: Write the proportion equation
   1,347.29 : 1,858.61 = 780.09 : x
2. Step 2: Convert to fraction form
   1,347.29/1,858.61 = 780.09/x
3. Step 3: Cross multiply
   1,347.29x = 1,858.61 × 780.09
4. Step 4: Simplify right side
   1,347.29x = 1,449,883.07
5. Step 5: Solve for x
   x = 1,449,883.07/1,347.29
6. Step 6: Final answer
   x = 1,076.15