Finding the Fourth Proportional to 1,919.63, 2,648.32 and 1,290.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,919.63 : 2,648.32 = 1,290.56 : x
2. Step 2: Convert to fraction form
   1,919.63/2,648.32 = 1,290.56/x
3. Step 3: Cross multiply
   1,919.63x = 2,648.32 × 1,290.56
4. Step 4: Simplify right side
   1,919.63x = 3,417,815.86
5. Step 5: Solve for x
   x = 3,417,815.86/1,919.63
6. Step 6: Final answer
   x = 1,780.46