Finding the Fourth Proportional to 1,191.60, 1,644.38 and 667.62

Step by Step Solution

1. Step 1: Write the proportion equation
   1,191.60 : 1,644.38 = 667.62 : x
2. Step 2: Convert to fraction form
   1,191.60/1,644.38 = 667.62/x
3. Step 3: Cross multiply
   1,191.60x = 1,644.38 × 667.62
4. Step 4: Simplify right side
   1,191.60x = 1,097,820.98
5. Step 5: Solve for x
   x = 1,097,820.98/1,191.60
6. Step 6: Final answer
   x = 921.30