Finding the Fourth Proportional to 1,191.86, 1,644.77 and 667.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,191.86 : 1,644.77 = 667.89 : x
2. Step 2: Convert to fraction form
   1,191.86/1,644.77 = 667.89/x
3. Step 3: Cross multiply
   1,191.86x = 1,644.77 × 667.89
4. Step 4: Simplify right side
   1,191.86x = 1,098,531.22
5. Step 5: Solve for x
   x = 1,098,531.22/1,191.86
6. Step 6: Final answer
   x = 921.70