Finding the Fourth Proportional to 1,173.50, 1,619.90 and 769.91

Step by Step Solution

1. Step 1: Write the proportion equation
   1,173.50 : 1,619.90 = 769.91 : x
2. Step 2: Convert to fraction form
   1,173.50/1,619.90 = 769.91/x
3. Step 3: Cross multiply
   1,173.50x = 1,619.90 × 769.91
4. Step 4: Simplify right side
   1,173.50x = 1,247,165.26
5. Step 5: Solve for x
   x = 1,247,165.26/1,173.50
6. Step 6: Final answer
   x = 1,062.78