Finding the Fourth Proportional to 1,191.06, 1,643.76 and 667.17

Step by Step Solution

1. Step 1: Write the proportion equation
   1,191.06 : 1,643.76 = 667.17 : x
2. Step 2: Convert to fraction form
   1,191.06/1,643.76 = 667.17/x
3. Step 3: Cross multiply
   1,191.06x = 1,643.76 × 667.17
4. Step 4: Simplify right side
   1,191.06x = 1,096,667.36
5. Step 5: Solve for x
   x = 1,096,667.36/1,191.06
6. Step 6: Final answer
   x = 920.75