Finding the Fourth Proportional to 1,218.58, 1,681.15 and 845.86

Step by Step Solution

1. Step 1: Write the proportion equation
   1,218.58 : 1,681.15 = 845.86 : x
2. Step 2: Convert to fraction form
   1,218.58/1,681.15 = 845.86/x
3. Step 3: Cross multiply
   1,218.58x = 1,681.15 × 845.86
4. Step 4: Simplify right side
   1,218.58x = 1,422,017.54
5. Step 5: Solve for x
   x = 1,422,017.54/1,218.58
6. Step 6: Final answer
   x = 1,166.95