Finding the Fourth Proportional to 2,117.31, 2,922.67 and 1,278.05

Step by Step Solution

1. Step 1: Write the proportion equation
   2,117.31 : 2,922.67 = 1,278.05 : x
2. Step 2: Convert to fraction form
   2,117.31/2,922.67 = 1,278.05/x
3. Step 3: Cross multiply
   2,117.31x = 2,922.67 × 1,278.05
4. Step 4: Simplify right side
   2,117.31x = 3,735,318.39
5. Step 5: Solve for x
   x = 3,735,318.39/2,117.31
6. Step 6: Final answer
   x = 1,764.18