Finding the Fourth Proportional to 2,385.72, 3,579.56 and 1,288.80

Step by Step Solution

1. Step 1: Write the proportion equation
   2,385.72 : 3,579.56 = 1,288.80 : x
2. Step 2: Convert to fraction form
   2,385.72/3,579.56 = 1,288.80/x
3. Step 3: Cross multiply
   2,385.72x = 3,579.56 × 1,288.80
4. Step 4: Simplify right side
   2,385.72x = 4,613,336.93
5. Step 5: Solve for x
   x = 4,613,336.93/2,385.72
6. Step 6: Final answer
   x = 1,933.73