Finding the Fourth Proportional to 1,386.42, 1,907.54 and 1,199.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,386.42 : 1,907.54 = 1,199.30 : x
2. Step 2: Convert to fraction form
   1,386.42/1,907.54 = 1,199.30/x
3. Step 3: Cross multiply
   1,386.42x = 1,907.54 × 1,199.30
4. Step 4: Simplify right side
   1,386.42x = 2,287,712.72
5. Step 5: Solve for x
   x = 2,287,712.72/1,386.42
6. Step 6: Final answer
   x = 1,650.09