Finding the Fourth Proportional to 1,291.89, 1,938.69 and 561.54

Step by Step Solution

1. Step 1: Write the proportion equation
   1,291.89 : 1,938.69 = 561.54 : x
2. Step 2: Convert to fraction form
   1,291.89/1,938.69 = 561.54/x
3. Step 3: Cross multiply
   1,291.89x = 1,938.69 × 561.54
4. Step 4: Simplify right side
   1,291.89x = 1,088,651.98
5. Step 5: Solve for x
   x = 1,088,651.98/1,291.89
6. Step 6: Final answer
   x = 842.68