Finding the Fourth Proportional to 1,111.23, 1,533.44 and 691.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.23 : 1,533.44 = 691.57 : x
2. Step 2: Convert to fraction form
   1,111.23/1,533.44 = 691.57/x
3. Step 3: Cross multiply
   1,111.23x = 1,533.44 × 691.57
4. Step 4: Simplify right side
   1,111.23x = 1,060,480.86
5. Step 5: Solve for x
   x = 1,060,480.86/1,111.23
6. Step 6: Final answer
   x = 954.33