Finding the Fourth Proportional to 1,091.76, 1,633.18 and 909.40

Step by Step Solution

1. Step 1: Write the proportion equation
   1,091.76 : 1,633.18 = 909.40 : x
2. Step 2: Convert to fraction form
   1,091.76/1,633.18 = 909.40/x
3. Step 3: Cross multiply
   1,091.76x = 1,633.18 × 909.40
4. Step 4: Simplify right side
   1,091.76x = 1,485,213.89
5. Step 5: Solve for x
   x = 1,485,213.89/1,091.76
6. Step 6: Final answer
   x = 1,360.38