Finding the Fourth Proportional to 1,192.86, 1,789.47 and 645.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,192.86 : 1,789.47 = 645.12 : x
2. Step 2: Convert to fraction form
   1,192.86/1,789.47 = 645.12/x
3. Step 3: Cross multiply
   1,192.86x = 1,789.47 × 645.12
4. Step 4: Simplify right side
   1,192.86x = 1,154,422.89
5. Step 5: Solve for x
   x = 1,154,422.89/1,192.86
6. Step 6: Final answer
   x = 967.78