Finding the Fourth Proportional to 1,145.80, 1,686.27 and 1,145.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,145.80 : 1,686.27 = 1,145.80 : x
2. Step 2: Convert to fraction form
   1,145.80/1,686.27 = 1,145.80/x
3. Step 3: Cross multiply
   1,145.80x = 1,686.27 × 1,145.80
4. Step 4: Simplify right side
   1,145.80x = 1,932,128.17
5. Step 5: Solve for x
   x = 1,932,128.17/1,145.80
6. Step 6: Final answer
   x = 1,686.27