Finding the Fourth Proportional to 2,112.42, 2,915.76 and 1,228.58

Step by Step Solution

1. Step 1: Write the proportion equation
   2,112.42 : 2,915.76 = 1,228.58 : x
2. Step 2: Convert to fraction form
   2,112.42/2,915.76 = 1,228.58/x
3. Step 3: Cross multiply
   2,112.42x = 2,915.76 × 1,228.58
4. Step 4: Simplify right side
   2,112.42x = 3,582,244.42
5. Step 5: Solve for x
   x = 3,582,244.42/2,112.42
6. Step 6: Final answer
   x = 1,695.80