Finding the Fourth Proportional to 1,870.26, 2,578.56 and 1,279.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,870.26 : 2,578.56 = 1,279.78 : x
2. Step 2: Convert to fraction form
   1,870.26/2,578.56 = 1,279.78/x
3. Step 3: Cross multiply
   1,870.26x = 2,578.56 × 1,279.78
4. Step 4: Simplify right side
   1,870.26x = 3,299,989.52
5. Step 5: Solve for x
   x = 3,299,989.52/1,870.26
6. Step 6: Final answer
   x = 1,764.45