Finding the Fourth Proportional to 1,087.50, 1,499.67 and 890.40

Step by Step Solution

1. Step 1: Write the proportion equation
   1,087.50 : 1,499.67 = 890.40 : x
2. Step 2: Convert to fraction form
   1,087.50/1,499.67 = 890.40/x
3. Step 3: Cross multiply
   1,087.50x = 1,499.67 × 890.40
4. Step 4: Simplify right side
   1,087.50x = 1,335,306.17
5. Step 5: Solve for x
   x = 1,335,306.17/1,087.50
6. Step 6: Final answer
   x = 1,227.87