Finding the Fourth Proportional to 1,279.50, 1,918.53 and 585.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,279.50 : 1,918.53 = 585.78 : x
2. Step 2: Convert to fraction form
   1,279.50/1,918.53 = 585.78/x
3. Step 3: Cross multiply
   1,279.50x = 1,918.53 × 585.78
4. Step 4: Simplify right side
   1,279.50x = 1,123,836.50
5. Step 5: Solve for x
   x = 1,123,836.50/1,279.50
6. Step 6: Final answer
   x = 878.34