Finding the Fourth Proportional to 913.82, 1,259.56 and 879.80

Step by Step Solution

1. Step 1: Write the proportion equation
   913.82 : 1,259.56 = 879.80 : x
2. Step 2: Convert to fraction form
   913.82/1,259.56 = 879.80/x
3. Step 3: Cross multiply
   913.82x = 1,259.56 × 879.80
4. Step 4: Simplify right side
   913.82x = 1,108,160.89
5. Step 5: Solve for x
   x = 1,108,160.89/913.82
6. Step 6: Final answer
   x = 1,212.67