Finding the Fourth Proportional to 1,445.35, 1,993.94 and 978.79

Step by Step Solution

1. Step 1: Write the proportion equation
   1,445.35 : 1,993.94 = 978.79 : x
2. Step 2: Convert to fraction form
   1,445.35/1,993.94 = 978.79/x
3. Step 3: Cross multiply
   1,445.35x = 1,993.94 × 978.79
4. Step 4: Simplify right side
   1,445.35x = 1,951,643.64
5. Step 5: Solve for x
   x = 1,951,643.64/1,445.35
6. Step 6: Final answer
   x = 1,350.29