Finding the Fourth Proportional to 1,222.58, 1,685.50 and 802.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,222.58 : 1,685.50 = 802.78 : x
2. Step 2: Convert to fraction form
   1,222.58/1,685.50 = 802.78/x
3. Step 3: Cross multiply
   1,222.58x = 1,685.50 × 802.78
4. Step 4: Simplify right side
   1,222.58x = 1,353,079.47
5. Step 5: Solve for x
   x = 1,353,079.47/1,222.58
6. Step 6: Final answer
   x = 1,106.74