Finding the Fourth Proportional to 1,129.89, 1,559.88 and 776.03

Step by Step Solution

1. Step 1: Write the proportion equation
   1,129.89 : 1,559.88 = 776.03 : x
2. Step 2: Convert to fraction form
   1,129.89/1,559.88 = 776.03/x
3. Step 3: Cross multiply
   1,129.89x = 1,559.88 × 776.03
4. Step 4: Simplify right side
   1,129.89x = 1,210,505.88
5. Step 5: Solve for x
   x = 1,210,505.88/1,129.89
6. Step 6: Final answer
   x = 1,071.34