Finding the Fourth Proportional to 1,561.90, 2,341.20 and 728.27

Step by Step Solution

1. Step 1: Write the proportion equation
   1,561.90 : 2,341.20 = 728.27 : x
2. Step 2: Convert to fraction form
   1,561.90/2,341.20 = 728.27/x
3. Step 3: Cross multiply
   1,561.90x = 2,341.20 × 728.27
4. Step 4: Simplify right side
   1,561.90x = 1,705,018.94
5. Step 5: Solve for x
   x = 1,705,018.94/1,561.90
6. Step 6: Final answer
   x = 1,091.63