Finding the Fourth Proportional to 1,178.15, 1,620.88 and 1,172.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,178.15 : 1,620.88 = 1,172.69 : x
2. Step 2: Convert to fraction form
   1,178.15/1,620.88 = 1,172.69/x
3. Step 3: Cross multiply
   1,178.15x = 1,620.88 × 1,172.69
4. Step 4: Simplify right side
   1,178.15x = 1,900,789.77
5. Step 5: Solve for x
   x = 1,900,789.77/1,178.15
6. Step 6: Final answer
   x = 1,613.37