Finding the Fourth Proportional to 2,599.90, 3,588.10 and 1,421.15

Step by Step Solution

1. Step 1: Write the proportion equation
   2,599.90 : 3,588.10 = 1,421.15 : x
2. Step 2: Convert to fraction form
   2,599.90/3,588.10 = 1,421.15/x
3. Step 3: Cross multiply
   2,599.90x = 3,588.10 × 1,421.15
4. Step 4: Simplify right side
   2,599.90x = 5,099,214.82
5. Step 5: Solve for x
   x = 5,099,214.82/2,599.90
6. Step 6: Final answer
   x = 1,961.31