Finding the Fourth Proportional to 2,117.84, 3,178.56 and 820.22

Step by Step Solution

1. Step 1: Write the proportion equation
   2,117.84 : 3,178.56 = 820.22 : x
2. Step 2: Convert to fraction form
   2,117.84/3,178.56 = 820.22/x
3. Step 3: Cross multiply
   2,117.84x = 3,178.56 × 820.22
4. Step 4: Simplify right side
   2,117.84x = 2,607,118.48
5. Step 5: Solve for x
   x = 2,607,118.48/2,117.84
6. Step 6: Final answer
   x = 1,231.03