Finding the Fourth Proportional to 1,393.52, 2,086.20 and 1,072.64

Step by Step Solution

1. Step 1: Write the proportion equation
   1,393.52 : 2,086.20 = 1,072.64 : x
2. Step 2: Convert to fraction form
   1,393.52/2,086.20 = 1,072.64/x
3. Step 3: Cross multiply
   1,393.52x = 2,086.20 × 1,072.64
4. Step 4: Simplify right side
   1,393.52x = 2,237,741.57
5. Step 5: Solve for x
   x = 2,237,741.57/1,393.52
6. Step 6: Final answer
   x = 1,605.82