Finding the Fourth Proportional to 1,091.90, 1,506.78 and 619.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,091.90 : 1,506.78 = 619.83 : x
2. Step 2: Convert to fraction form
   1,091.90/1,506.78 = 619.83/x
3. Step 3: Cross multiply
   1,091.90x = 1,506.78 × 619.83
4. Step 4: Simplify right side
   1,091.90x = 933,955.42
5. Step 5: Solve for x
   x = 933,955.42/1,091.90
6. Step 6: Final answer
   x = 855.35