Finding the Fourth Proportional to 2,112.18, 2,915.61 and 1,890.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,112.18 : 2,915.61 = 1,890.72 : x
2. Step 2: Convert to fraction form
   2,112.18/2,915.61 = 1,890.72/x
3. Step 3: Cross multiply
   2,112.18x = 2,915.61 × 1,890.72
4. Step 4: Simplify right side
   2,112.18x = 5,512,602.14
5. Step 5: Solve for x
   x = 5,512,602.14/2,112.18
6. Step 6: Final answer
   x = 2,609.91