Finding the Fourth Proportional to 1,570.74, 2,356.76 and 877.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,570.74 : 2,356.76 = 877.89 : x
2. Step 2: Convert to fraction form
   1,570.74/2,356.76 = 877.89/x
3. Step 3: Cross multiply
   1,570.74x = 2,356.76 × 877.89
4. Step 4: Simplify right side
   1,570.74x = 2,068,976.04
5. Step 5: Solve for x
   x = 2,068,976.04/1,570.74
6. Step 6: Final answer
   x = 1,317.20