Finding the Fourth Proportional to 1,111.08, 1,661.76 and 776.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.08 : 1,661.76 = 776.56 : x
2. Step 2: Convert to fraction form
   1,111.08/1,661.76 = 776.56/x
3. Step 3: Cross multiply
   1,111.08x = 1,661.76 × 776.56
4. Step 4: Simplify right side
   1,111.08x = 1,290,456.35
5. Step 5: Solve for x
   x = 1,290,456.35/1,111.08
6. Step 6: Final answer
   x = 1,161.44