Finding the Fourth Proportional to 1,391.77, 1,918.72 and 1,348.64

Step by Step Solution

1. Step 1: Write the proportion equation
   1,391.77 : 1,918.72 = 1,348.64 : x
2. Step 2: Convert to fraction form
   1,391.77/1,918.72 = 1,348.64/x
3. Step 3: Cross multiply
   1,391.77x = 1,918.72 × 1,348.64
4. Step 4: Simplify right side
   1,391.77x = 2,587,662.54
5. Step 5: Solve for x
   x = 2,587,662.54/1,391.77
6. Step 6: Final answer
   x = 1,859.26