Finding the Fourth Proportional to 1,351.15, 1,862.40 and 978.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,351.15 : 1,862.40 = 978.15 : x
2. Step 2: Convert to fraction form
   1,351.15/1,862.40 = 978.15/x
3. Step 3: Cross multiply
   1,351.15x = 1,862.40 × 978.15
4. Step 4: Simplify right side
   1,351.15x = 1,821,706.56
5. Step 5: Solve for x
   x = 1,821,706.56/1,351.15
6. Step 6: Final answer
   x = 1,348.26