Finding the Fourth Proportional to 861.38, 1,189.78 and 848.42

Step by Step Solution

1. Step 1: Write the proportion equation
   861.38 : 1,189.78 = 848.42 : x
2. Step 2: Convert to fraction form
   861.38/1,189.78 = 848.42/x
3. Step 3: Cross multiply
   861.38x = 1,189.78 × 848.42
4. Step 4: Simplify right side
   861.38x = 1,009,429.54
5. Step 5: Solve for x
   x = 1,009,429.54/861.38
6. Step 6: Final answer
   x = 1,171.88