Finding the Fourth Proportional to 1,190.72, 1,643.12 and 693.28

Step by Step Solution

1. Step 1: Write the proportion equation
   1,190.72 : 1,643.12 = 693.28 : x
2. Step 2: Convert to fraction form
   1,190.72/1,643.12 = 693.28/x
3. Step 3: Cross multiply
   1,190.72x = 1,643.12 × 693.28
4. Step 4: Simplify right side
   1,190.72x = 1,139,143.42
5. Step 5: Solve for x
   x = 1,139,143.42/1,190.72
6. Step 6: Final answer
   x = 956.68