Finding the Fourth Proportional to 2,385.90, 3,580.78 and 1,645.06

Step by Step Solution

1. Step 1: Write the proportion equation
   2,385.90 : 3,580.78 = 1,645.06 : x
2. Step 2: Convert to fraction form
   2,385.90/3,580.78 = 1,645.06/x
3. Step 3: Cross multiply
   2,385.90x = 3,580.78 × 1,645.06
4. Step 4: Simplify right side
   2,385.90x = 5,890,580.41
5. Step 5: Solve for x
   x = 5,890,580.41/2,385.90
6. Step 6: Final answer
   x = 2,468.91