Finding the Fourth Proportional to 1,261.89, 1,739.89 and 819.63

Step by Step Solution

1. Step 1: Write the proportion equation
   1,261.89 : 1,739.89 = 819.63 : x
2. Step 2: Convert to fraction form
   1,261.89/1,739.89 = 819.63/x
3. Step 3: Cross multiply
   1,261.89x = 1,739.89 × 819.63
4. Step 4: Simplify right side
   1,261.89x = 1,426,066.04
5. Step 5: Solve for x
   x = 1,426,066.04/1,261.89
6. Step 6: Final answer
   x = 1,130.10