Finding the Fourth Proportional to 1,315.69, 1,972.16 and 585.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,315.69 : 1,972.16 = 585.78 : x
2. Step 2: Convert to fraction form
   1,315.69/1,972.16 = 585.78/x
3. Step 3: Cross multiply
   1,315.69x = 1,972.16 × 585.78
4. Step 4: Simplify right side
   1,315.69x = 1,155,251.88
5. Step 5: Solve for x
   x = 1,155,251.88/1,315.69
6. Step 6: Final answer
   x = 878.06