Finding the Fourth Proportional to 1,521.76, 2,099.88 and 858.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,521.76 : 2,099.88 = 858.50 : x
2. Step 2: Convert to fraction form
   1,521.76/2,099.88 = 858.50/x
3. Step 3: Cross multiply
   1,521.76x = 2,099.88 × 858.50
4. Step 4: Simplify right side
   1,521.76x = 1,802,746.98
5. Step 5: Solve for x
   x = 1,802,746.98/1,521.76
6. Step 6: Final answer
   x = 1,184.65