Finding the Fourth Proportional to 1,089.12, 1,502.64 and 867.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,089.12 : 1,502.64 = 867.72 : x
2. Step 2: Convert to fraction form
   1,089.12/1,502.64 = 867.72/x
3. Step 3: Cross multiply
   1,089.12x = 1,502.64 × 867.72
4. Step 4: Simplify right side
   1,089.12x = 1,303,870.78
5. Step 5: Solve for x
   x = 1,303,870.78/1,089.12
6. Step 6: Final answer
   x = 1,197.18