Finding the Fourth Proportional to 2,561.60, 3,838.85 and 1,869.86

Step by Step Solution

1. Step 1: Write the proportion equation
   2,561.60 : 3,838.85 = 1,869.86 : x
2. Step 2: Convert to fraction form
   2,561.60/3,838.85 = 1,869.86/x
3. Step 3: Cross multiply
   2,561.60x = 3,838.85 × 1,869.86
4. Step 4: Simplify right side
   2,561.60x = 7,178,112.06
5. Step 5: Solve for x
   x = 7,178,112.06/2,561.60
6. Step 6: Final answer
   x = 2,802.20