Finding the Fourth Proportional to 2,109.62, 2,911.28 and 1,178.12

Step by Step Solution

1. Step 1: Write the proportion equation
   2,109.62 : 2,911.28 = 1,178.12 : x
2. Step 2: Convert to fraction form
   2,109.62/2,911.28 = 1,178.12/x
3. Step 3: Cross multiply
   2,109.62x = 2,911.28 × 1,178.12
4. Step 4: Simplify right side
   2,109.62x = 3,429,837.19
5. Step 5: Solve for x
   x = 3,429,837.19/2,109.62
6. Step 6: Final answer
   x = 1,625.81