Finding the Fourth Proportional to 1,111.72, 1,668.09 and 591.59

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.72 : 1,668.09 = 591.59 : x
2. Step 2: Convert to fraction form
   1,111.72/1,668.09 = 591.59/x
3. Step 3: Cross multiply
   1,111.72x = 1,668.09 × 591.59
4. Step 4: Simplify right side
   1,111.72x = 986,814.06
5. Step 5: Solve for x
   x = 986,814.06/1,111.72
6. Step 6: Final answer
   x = 887.65