Finding the Fourth Proportional to 1,521.61, 2,099.76 and 858.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,521.61 : 2,099.76 = 858.60 : x
2. Step 2: Convert to fraction form
   1,521.61/2,099.76 = 858.60/x
3. Step 3: Cross multiply
   1,521.61x = 2,099.76 × 858.60
4. Step 4: Simplify right side
   1,521.61x = 1,802,853.94
5. Step 5: Solve for x
   x = 1,802,853.94/1,521.61
6. Step 6: Final answer
   x = 1,184.83