Finding the Fourth Proportional to 2,117.52, 2,922.42 and 1,221.47

Step by Step Solution

1. Step 1: Write the proportion equation
   2,117.52 : 2,922.42 = 1,221.47 : x
2. Step 2: Convert to fraction form
   2,117.52/2,922.42 = 1,221.47/x
3. Step 3: Cross multiply
   2,117.52x = 2,922.42 × 1,221.47
4. Step 4: Simplify right side
   2,117.52x = 3,569,648.36
5. Step 5: Solve for x
   x = 3,569,648.36/2,117.52
6. Step 6: Final answer
   x = 1,685.77