Finding the Fourth Proportional to 1,111.61, 1,666.38 and 699.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.61 : 1,666.38 = 699.50 : x
2. Step 2: Convert to fraction form
   1,111.61/1,666.38 = 699.50/x
3. Step 3: Cross multiply
   1,111.61x = 1,666.38 × 699.50
4. Step 4: Simplify right side
   1,111.61x = 1,165,632.81
5. Step 5: Solve for x
   x = 1,165,632.81/1,111.61
6. Step 6: Final answer
   x = 1,048.60