Finding the Fourth Proportional to 1,289.34, 1,779.76 and 765.38

Step by Step Solution

1. Step 1: Write the proportion equation
   1,289.34 : 1,779.76 = 765.38 : x
2. Step 2: Convert to fraction form
   1,289.34/1,779.76 = 765.38/x
3. Step 3: Cross multiply
   1,289.34x = 1,779.76 × 765.38
4. Step 4: Simplify right side
   1,289.34x = 1,362,180.46
5. Step 5: Solve for x
   x = 1,362,180.46/1,289.34
6. Step 6: Final answer
   x = 1,056.49