Finding the Fourth Proportional to 1,309.51, 1,961.69 and 760.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,309.51 : 1,961.69 = 760.55 : x
2. Step 2: Convert to fraction form
   1,309.51/1,961.69 = 760.55/x
3. Step 3: Cross multiply
   1,309.51x = 1,961.69 × 760.55
4. Step 4: Simplify right side
   1,309.51x = 1,491,953.52
5. Step 5: Solve for x
   x = 1,491,953.52/1,309.51
6. Step 6: Final answer
   x = 1,139.32