Finding the Fourth Proportional to 1,087.72, 1,631.59 and 764.54

Step by Step Solution

1. Step 1: Write the proportion equation
   1,087.72 : 1,631.59 = 764.54 : x
2. Step 2: Convert to fraction form
   1,087.72/1,631.59 = 764.54/x
3. Step 3: Cross multiply
   1,087.72x = 1,631.59 × 764.54
4. Step 4: Simplify right side
   1,087.72x = 1,247,415.82
5. Step 5: Solve for x
   x = 1,247,415.82/1,087.72
6. Step 6: Final answer
   x = 1,146.82