Finding the Fourth Proportional to 6,659.39, 9,987.37 and 1,978.15

Step by Step Solution

1. Step 1: Write the proportion equation
   6,659.39 : 9,987.37 = 1,978.15 : x
2. Step 2: Convert to fraction form
   6,659.39/9,987.37 = 1,978.15/x
3. Step 3: Cross multiply
   6,659.39x = 9,987.37 × 1,978.15
4. Step 4: Simplify right side
   6,659.39x = 19,756,486.05
5. Step 5: Solve for x
   x = 19,756,486.05/6,659.39
6. Step 6: Final answer
   x = 2,966.71