Finding the Fourth Proportional to 1,190.78, 1,643.39 and 693.47

Step by Step Solution

1. Step 1: Write the proportion equation
   1,190.78 : 1,643.39 = 693.47 : x
2. Step 2: Convert to fraction form
   1,190.78/1,643.39 = 693.47/x
3. Step 3: Cross multiply
   1,190.78x = 1,643.39 × 693.47
4. Step 4: Simplify right side
   1,190.78x = 1,139,642.30
5. Step 5: Solve for x
   x = 1,139,642.30/1,190.78
6. Step 6: Final answer
   x = 957.05