Finding the Fourth Proportional to 1,434.59, 1,977.63 and 1,139.96

Step by Step Solution

1. Step 1: Write the proportion equation
   1,434.59 : 1,977.63 = 1,139.96 : x
2. Step 2: Convert to fraction form
   1,434.59/1,977.63 = 1,139.96/x
3. Step 3: Cross multiply
   1,434.59x = 1,977.63 × 1,139.96
4. Step 4: Simplify right side
   1,434.59x = 2,254,409.21
5. Step 5: Solve for x
   x = 2,254,409.21/1,434.59
6. Step 6: Final answer
   x = 1,571.47