Finding the Fourth Proportional to 1,488.96, 2,231.28 and 1,386.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,488.96 : 2,231.28 = 1,386.72 : x
2. Step 2: Convert to fraction form
   1,488.96/2,231.28 = 1,386.72/x
3. Step 3: Cross multiply
   1,488.96x = 2,231.28 × 1,386.72
4. Step 4: Simplify right side
   1,488.96x = 3,094,160.60
5. Step 5: Solve for x
   x = 3,094,160.60/1,488.96
6. Step 6: Final answer
   x = 2,078.07