Finding the Fourth Proportional to 1,499.72, 2,069.55 and 870.21

Step by Step Solution

1. Step 1: Write the proportion equation
   1,499.72 : 2,069.55 = 870.21 : x
2. Step 2: Convert to fraction form
   1,499.72/2,069.55 = 870.21/x
3. Step 3: Cross multiply
   1,499.72x = 2,069.55 × 870.21
4. Step 4: Simplify right side
   1,499.72x = 1,800,943.11
5. Step 5: Solve for x
   x = 1,800,943.11/1,499.72
6. Step 6: Final answer
   x = 1,200.86