Finding the Fourth Proportional to 1,188.25, 1,639.89 and 716.38

Step by Step Solution

1. Step 1: Write the proportion equation
   1,188.25 : 1,639.89 = 716.38 : x
2. Step 2: Convert to fraction form
   1,188.25/1,639.89 = 716.38/x
3. Step 3: Cross multiply
   1,188.25x = 1,639.89 × 716.38
4. Step 4: Simplify right side
   1,188.25x = 1,174,780.30
5. Step 5: Solve for x
   x = 1,174,780.30/1,188.25
6. Step 6: Final answer
   x = 988.67