Finding the Fourth Proportional to 1,089.13, 1,501.89 and 902.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,089.13 : 1,501.89 = 902.20 : x
2. Step 2: Convert to fraction form
   1,089.13/1,501.89 = 902.20/x
3. Step 3: Cross multiply
   1,089.13x = 1,501.89 × 902.20
4. Step 4: Simplify right side
   1,089.13x = 1,355,005.16
5. Step 5: Solve for x
   x = 1,355,005.16/1,089.13
6. Step 6: Final answer
   x = 1,244.12