Finding the Fourth Proportional to 2,561.36, 3,839.61 and 917.06

Step by Step Solution

1. Step 1: Write the proportion equation
   2,561.36 : 3,839.61 = 917.06 : x
2. Step 2: Convert to fraction form
   2,561.36/3,839.61 = 917.06/x
3. Step 3: Cross multiply
   2,561.36x = 3,839.61 × 917.06
4. Step 4: Simplify right side
   2,561.36x = 3,521,152.75
5. Step 5: Solve for x
   x = 3,521,152.75/2,561.36
6. Step 6: Final answer
   x = 1,374.72