Finding the Fourth Proportional to 1,415.55, 2,127.42 and 1,317.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,415.55 : 2,127.42 = 1,317.12 : x
2. Step 2: Convert to fraction form
   1,415.55/2,127.42 = 1,317.12/x
3. Step 3: Cross multiply
   1,415.55x = 2,127.42 × 1,317.12
4. Step 4: Simplify right side
   1,415.55x = 2,802,067.43
5. Step 5: Solve for x
   x = 2,802,067.43/1,415.55
6. Step 6: Final answer
   x = 1,979.49