Finding the Fourth Proportional to 1,015.40, 1,519.86 and 527.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,015.40 : 1,519.86 = 527.78 : x
2. Step 2: Convert to fraction form
   1,015.40/1,519.86 = 527.78/x
3. Step 3: Cross multiply
   1,015.40x = 1,519.86 × 527.78
4. Step 4: Simplify right side
   1,015.40x = 802,151.71
5. Step 5: Solve for x
   x = 802,151.71/1,015.40
6. Step 6: Final answer
   x = 789.99