Finding the Fourth Proportional to 1,091.82, 1,507.20 and 777.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,091.82 : 1,507.20 = 777.30 : x
2. Step 2: Convert to fraction form
   1,091.82/1,507.20 = 777.30/x
3. Step 3: Cross multiply
   1,091.82x = 1,507.20 × 777.30
4. Step 4: Simplify right side
   1,091.82x = 1,171,546.56
5. Step 5: Solve for x
   x = 1,171,546.56/1,091.82
6. Step 6: Final answer
   x = 1,073.02