Finding the Fourth Proportional to 1,485.78, 2,049.20 and 1,386.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,485.78 : 2,049.20 = 1,386.42 : x
2. Step 2: Convert to fraction form
   1,485.78/2,049.20 = 1,386.42/x
3. Step 3: Cross multiply
   1,485.78x = 2,049.20 × 1,386.42
4. Step 4: Simplify right side
   1,485.78x = 2,841,051.86
5. Step 5: Solve for x
   x = 2,841,051.86/1,485.78
6. Step 6: Final answer
   x = 1,912.16