Finding the Fourth Proportional to 1,091.58, 1,636.89 and 398.01

Step by Step Solution

1. Step 1: Write the proportion equation
   1,091.58 : 1,636.89 = 398.01 : x
2. Step 2: Convert to fraction form
   1,091.58/1,636.89 = 398.01/x
3. Step 3: Cross multiply
   1,091.58x = 1,636.89 × 398.01
4. Step 4: Simplify right side
   1,091.58x = 651,498.59
5. Step 5: Solve for x
   x = 651,498.59/1,091.58
6. Step 6: Final answer
   x = 596.84