Finding the Fourth Proportional to 3,139.40, 4,705.68 and 1,190.72

Step by Step Solution

1. Step 1: Write the proportion equation
   3,139.40 : 4,705.68 = 1,190.72 : x
2. Step 2: Convert to fraction form
   3,139.40/4,705.68 = 1,190.72/x
3. Step 3: Cross multiply
   3,139.40x = 4,705.68 × 1,190.72
4. Step 4: Simplify right side
   3,139.40x = 5,603,147.29
5. Step 5: Solve for x
   x = 5,603,147.29/3,139.40
6. Step 6: Final answer
   x = 1,784.78