Finding the Fourth Proportional to 1,128.50, 1,693.61 and 784.25

Step by Step Solution

1. Step 1: Write the proportion equation
   1,128.50 : 1,693.61 = 784.25 : x
2. Step 2: Convert to fraction form
   1,128.50/1,693.61 = 784.25/x
3. Step 3: Cross multiply
   1,128.50x = 1,693.61 × 784.25
4. Step 4: Simplify right side
   1,128.50x = 1,328,213.64
5. Step 5: Solve for x
   x = 1,328,213.64/1,128.50
6. Step 6: Final answer
   x = 1,176.97