Finding the Fourth Proportional to 1,091.34, 1,636.56 and 397.86

Step by Step Solution

1. Step 1: Write the proportion equation
   1,091.34 : 1,636.56 = 397.86 : x
2. Step 2: Convert to fraction form
   1,091.34/1,636.56 = 397.86/x
3. Step 3: Cross multiply
   1,091.34x = 1,636.56 × 397.86
4. Step 4: Simplify right side
   1,091.34x = 651,121.76
5. Step 5: Solve for x
   x = 651,121.76/1,091.34
6. Step 6: Final answer
   x = 596.63