Finding the Fourth Proportional to 1,131.94, 1,696.52 and 643.51

Step by Step Solution

1. Step 1: Write the proportion equation
   1,131.94 : 1,696.52 = 643.51 : x
2. Step 2: Convert to fraction form
   1,131.94/1,696.52 = 643.51/x
3. Step 3: Cross multiply
   1,131.94x = 1,696.52 × 643.51
4. Step 4: Simplify right side
   1,131.94x = 1,091,724.37
5. Step 5: Solve for x
   x = 1,091,724.37/1,131.94
6. Step 6: Final answer
   x = 964.47