Finding the Fourth Proportional to 1,886.72, 2,829.12 and 860

Step by Step Solution

1. Step 1: Write the proportion equation
   1,886.72 : 2,829.12 = 860 : x
2. Step 2: Convert to fraction form
   1,886.72/2,829.12 = 860/x
3. Step 3: Cross multiply
   1,886.72x = 2,829.12 × 860
4. Step 4: Simplify right side
   1,886.72x = 2,433,043.20
5. Step 5: Solve for x
   x = 2,433,043.20/1,886.72
6. Step 6: Final answer
   x = 1,289.56