Finding the Fourth Proportional to 1,019.86, 1,528.74 and 580.54

Step by Step Solution

1. Step 1: Write the proportion equation
   1,019.86 : 1,528.74 = 580.54 : x
2. Step 2: Convert to fraction form
   1,019.86/1,528.74 = 580.54/x
3. Step 3: Cross multiply
   1,019.86x = 1,528.74 × 580.54
4. Step 4: Simplify right side
   1,019.86x = 887,494.72
5. Step 5: Solve for x
   x = 887,494.72/1,019.86
6. Step 6: Final answer
   x = 870.21