Finding the Fourth Proportional to 1,915.50, 2,643.39 and 1,087.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,915.50 : 2,643.39 = 1,087.50 : x
2. Step 2: Convert to fraction form
   1,915.50/2,643.39 = 1,087.50/x
3. Step 3: Cross multiply
   1,915.50x = 2,643.39 × 1,087.50
4. Step 4: Simplify right side
   1,915.50x = 2,874,686.63
5. Step 5: Solve for x
   x = 2,874,686.63/1,915.50
6. Step 6: Final answer
   x = 1,500.75