Finding the Fourth Proportional to 1,639.69, 2,263.71 and 1,265.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,639.69 : 2,263.71 = 1,265.89 : x
2. Step 2: Convert to fraction form
   1,639.69/2,263.71 = 1,265.89/x
3. Step 3: Cross multiply
   1,639.69x = 2,263.71 × 1,265.89
4. Step 4: Simplify right side
   1,639.69x = 2,865,607.85
5. Step 5: Solve for x
   x = 2,865,607.85/1,639.69
6. Step 6: Final answer
   x = 1,747.65