Finding the Fourth Proportional to 1,069.48, 1,601.90 and 581.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,069.48 : 1,601.90 = 581.50 : x
2. Step 2: Convert to fraction form
   1,069.48/1,601.90 = 581.50/x
3. Step 3: Cross multiply
   1,069.48x = 1,601.90 × 581.50
4. Step 4: Simplify right side
   1,069.48x = 931,504.85
5. Step 5: Solve for x
   x = 931,504.85/1,069.48
6. Step 6: Final answer
   x = 870.99