Finding the Fourth Proportional to 1,139.34, 1,718.54 and 1,071.91

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.34 : 1,718.54 = 1,071.91 : x
2. Step 2: Convert to fraction form
   1,139.34/1,718.54 = 1,071.91/x
3. Step 3: Cross multiply
   1,139.34x = 1,718.54 × 1,071.91
4. Step 4: Simplify right side
   1,139.34x = 1,842,120.21
5. Step 5: Solve for x
   x = 1,842,120.21/1,139.34
6. Step 6: Final answer
   x = 1,616.83