Finding the Fourth Proportional to 1,570.55, 2,358.15 and 878.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,570.55 : 2,358.15 = 878.60 : x
2. Step 2: Convert to fraction form
   1,570.55/2,358.15 = 878.60/x
3. Step 3: Cross multiply
   1,570.55x = 2,358.15 × 878.60
4. Step 4: Simplify right side
   1,570.55x = 2,071,870.59
5. Step 5: Solve for x
   x = 2,071,870.59/1,570.55
6. Step 6: Final answer
   x = 1,319.20