Finding the Fourth Proportional to 1,188.96, 1,781.37 and 641.52

Step by Step Solution

1. Step 1: Write the proportion equation
   1,188.96 : 1,781.37 = 641.52 : x
2. Step 2: Convert to fraction form
   1,188.96/1,781.37 = 641.52/x
3. Step 3: Cross multiply
   1,188.96x = 1,781.37 × 641.52
4. Step 4: Simplify right side
   1,188.96x = 1,142,784.48
5. Step 5: Solve for x
   x = 1,142,784.48/1,188.96
6. Step 6: Final answer
   x = 961.16