Finding the Fourth Proportional to 1,002.69, 1,384.16 and 878.49

Step by Step Solution

1. Step 1: Write the proportion equation
   1,002.69 : 1,384.16 = 878.49 : x
2. Step 2: Convert to fraction form
   1,002.69/1,384.16 = 878.49/x
3. Step 3: Cross multiply
   1,002.69x = 1,384.16 × 878.49
4. Step 4: Simplify right side
   1,002.69x = 1,215,966.33
5. Step 5: Solve for x
   x = 1,215,966.33/1,002.69
6. Step 6: Final answer
   x = 1,212.70