Finding the Fourth Proportional to 1,111.14, 1,533.33 and 645.39

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.14 : 1,533.33 = 645.39 : x
2. Step 2: Convert to fraction form
   1,111.14/1,533.33 = 645.39/x
3. Step 3: Cross multiply
   1,111.14x = 1,533.33 × 645.39
4. Step 4: Simplify right side
   1,111.14x = 989,595.85
5. Step 5: Solve for x
   x = 989,595.85/1,111.14
6. Step 6: Final answer
   x = 890.61