Finding the Fourth Proportional to 1,069.91, 1,603.64 and 491.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,069.91 : 1,603.64 = 491.57 : x
2. Step 2: Convert to fraction form
   1,069.91/1,603.64 = 491.57/x
3. Step 3: Cross multiply
   1,069.91x = 1,603.64 × 491.57
4. Step 4: Simplify right side
   1,069.91x = 788,298.86
5. Step 5: Solve for x
   x = 788,298.86/1,069.91
6. Step 6: Final answer
   x = 736.79