Finding the Fourth Proportional to 1,987.38, 2,978.88 and 1,294.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,987.38 : 2,978.88 = 1,294.56 : x
2. Step 2: Convert to fraction form
   1,987.38/2,978.88 = 1,294.56/x
3. Step 3: Cross multiply
   1,987.38x = 2,978.88 × 1,294.56
4. Step 4: Simplify right side
   1,987.38x = 3,856,338.89
5. Step 5: Solve for x
   x = 3,856,338.89/1,987.38
6. Step 6: Final answer
   x = 1,940.41