Finding the Fourth Proportional to 1,123.79, 1,687.23 and 776.26

Step by Step Solution

1. Step 1: Write the proportion equation
   1,123.79 : 1,687.23 = 776.26 : x
2. Step 2: Convert to fraction form
   1,123.79/1,687.23 = 776.26/x
3. Step 3: Cross multiply
   1,123.79x = 1,687.23 × 776.26
4. Step 4: Simplify right side
   1,123.79x = 1,309,731.27
5. Step 5: Solve for x
   x = 1,309,731.27/1,123.79
6. Step 6: Final answer
   x = 1,165.46