Finding the Fourth Proportional to 8,585.61, 12,870.12 and 3,316.74

Step by Step Solution

1. Step 1: Write the proportion equation
   8,585.61 : 12,870.12 = 3,316.74 : x
2. Step 2: Convert to fraction form
   8,585.61/12,870.12 = 3,316.74/x
3. Step 3: Cross multiply
   8,585.61x = 12,870.12 × 3,316.74
4. Step 4: Simplify right side
   8,585.61x = 42,686,841.81
5. Step 5: Solve for x
   x = 42,686,841.81/8,585.61
6. Step 6: Final answer
   x = 4,971.91