Finding the Fourth Proportional to 2,128.82, 3,190.75 and 1,387.38

Step by Step Solution

1. Step 1: Write the proportion equation
   2,128.82 : 3,190.75 = 1,387.38 : x
2. Step 2: Convert to fraction form
   2,128.82/3,190.75 = 1,387.38/x
3. Step 3: Cross multiply
   2,128.82x = 3,190.75 × 1,387.38
4. Step 4: Simplify right side
   2,128.82x = 4,426,782.74
5. Step 5: Solve for x
   x = 4,426,782.74/2,128.82
6. Step 6: Final answer
   x = 2,079.45