Finding the Fourth Proportional to 1,438.48, 1,985.34 and 1,128.52

Step by Step Solution

1. Step 1: Write the proportion equation
   1,438.48 : 1,985.34 = 1,128.52 : x
2. Step 2: Convert to fraction form
   1,438.48/1,985.34 = 1,128.52/x
3. Step 3: Cross multiply
   1,438.48x = 1,985.34 × 1,128.52
4. Step 4: Simplify right side
   1,438.48x = 2,240,495.90
5. Step 5: Solve for x
   x = 2,240,495.90/1,438.48
6. Step 6: Final answer
   x = 1,557.54