Finding the Fourth Proportional to 2,131.38, 3,191.40 and 1,666.71

Step by Step Solution

1. Step 1: Write the proportion equation
   2,131.38 : 3,191.40 = 1,666.71 : x
2. Step 2: Convert to fraction form
   2,131.38/3,191.40 = 1,666.71/x
3. Step 3: Cross multiply
   2,131.38x = 3,191.40 × 1,666.71
4. Step 4: Simplify right side
   2,131.38x = 5,319,138.29
5. Step 5: Solve for x
   x = 5,319,138.29/2,131.38
6. Step 6: Final answer
   x = 2,495.63