Finding the Fourth Proportional to 1,386.42, 1,913.28 and 765.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,386.42 : 1,913.28 = 765.42 : x
2. Step 2: Convert to fraction form
   1,386.42/1,913.28 = 765.42/x
3. Step 3: Cross multiply
   1,386.42x = 1,913.28 × 765.42
4. Step 4: Simplify right side
   1,386.42x = 1,464,462.78
5. Step 5: Solve for x
   x = 1,464,462.78/1,386.42
6. Step 6: Final answer
   x = 1,056.29