Finding the Fourth Proportional to 2,128.23, 2,938.82 and 1,431.63

Step by Step Solution

1. Step 1: Write the proportion equation
   2,128.23 : 2,938.82 = 1,431.63 : x
2. Step 2: Convert to fraction form
   2,128.23/2,938.82 = 1,431.63/x
3. Step 3: Cross multiply
   2,128.23x = 2,938.82 × 1,431.63
4. Step 4: Simplify right side
   2,128.23x = 4,207,295.72
5. Step 5: Solve for x
   x = 4,207,295.72/2,128.23
6. Step 6: Final answer
   x = 1,976.90