Finding the Fourth Proportional to 2,117.72, 3,176.31 and 818.75

Step by Step Solution

1. Step 1: Write the proportion equation
   2,117.72 : 3,176.31 = 818.75 : x
2. Step 2: Convert to fraction form
   2,117.72/3,176.31 = 818.75/x
3. Step 3: Cross multiply
   2,117.72x = 3,176.31 × 818.75
4. Step 4: Simplify right side
   2,117.72x = 2,600,603.81
5. Step 5: Solve for x
   x = 2,600,603.81/2,117.72
6. Step 6: Final answer
   x = 1,228.02