Finding the Fourth Proportional to 1,533.67, 2,116.69 and 861.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,533.67 : 2,116.69 = 861.55 : x
2. Step 2: Convert to fraction form
   1,533.67/2,116.69 = 861.55/x
3. Step 3: Cross multiply
   1,533.67x = 2,116.69 × 861.55
4. Step 4: Simplify right side
   1,533.67x = 1,823,634.27
5. Step 5: Solve for x
   x = 1,823,634.27/1,533.67
6. Step 6: Final answer
   x = 1,189.07