Finding the Fourth Proportional to 1,111.91, 1,534.70 and 872.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.91 : 1,534.70 = 872.15 : x
2. Step 2: Convert to fraction form
   1,111.91/1,534.70 = 872.15/x
3. Step 3: Cross multiply
   1,111.91x = 1,534.70 × 872.15
4. Step 4: Simplify right side
   1,111.91x = 1,338,476.57
5. Step 5: Solve for x
   x = 1,338,476.57/1,111.91
6. Step 6: Final answer
   x = 1,203.77