Finding the Fourth Proportional to 1,385.31, 1,911.68 and 764.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,385.31 : 1,911.68 = 764.31 : x
2. Step 2: Convert to fraction form
   1,385.31/1,911.68 = 764.31/x
3. Step 3: Cross multiply
   1,385.31x = 1,911.68 × 764.31
4. Step 4: Simplify right side
   1,385.31x = 1,461,112.32
5. Step 5: Solve for x
   x = 1,461,112.32/1,385.31
6. Step 6: Final answer
   x = 1,054.72