Finding the Fourth Proportional to 2,561.63, 3,838.28 and 999.87

Step by Step Solution

1. Step 1: Write the proportion equation
   2,561.63 : 3,838.28 = 999.87 : x
2. Step 2: Convert to fraction form
   2,561.63/3,838.28 = 999.87/x
3. Step 3: Cross multiply
   2,561.63x = 3,838.28 × 999.87
4. Step 4: Simplify right side
   2,561.63x = 3,837,783.52
5. Step 5: Solve for x
   x = 3,837,783.52/2,561.63
6. Step 6: Final answer
   x = 1,498.18