Finding the Fourth Proportional to 1,398.17, 1,928.49 and 1,186.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,398.17 : 1,928.49 = 1,186.89 : x
2. Step 2: Convert to fraction form
   1,398.17/1,928.49 = 1,186.89/x
3. Step 3: Cross multiply
   1,398.17x = 1,928.49 × 1,186.89
4. Step 4: Simplify right side
   1,398.17x = 2,288,895.85
5. Step 5: Solve for x
   x = 2,288,895.85/1,398.17
6. Step 6: Final answer
   x = 1,637.07