Finding the Fourth Proportional to 1,488.47, 2,054.31 and 858.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,488.47 : 2,054.31 = 858.88 : x
2. Step 2: Convert to fraction form
   1,488.47/2,054.31 = 858.88/x
3. Step 3: Cross multiply
   1,488.47x = 2,054.31 × 858.88
4. Step 4: Simplify right side
   1,488.47x = 1,764,405.77
5. Step 5: Solve for x
   x = 1,764,405.77/1,488.47
6. Step 6: Final answer
   x = 1,185.38