Finding the Fourth Proportional to 1,111.26, 1,533.03 and 645.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.26 : 1,533.03 = 645.42 : x
2. Step 2: Convert to fraction form
   1,111.26/1,533.03 = 645.42/x
3. Step 3: Cross multiply
   1,111.26x = 1,533.03 × 645.42
4. Step 4: Simplify right side
   1,111.26x = 989,448.22
5. Step 5: Solve for x
   x = 989,448.22/1,111.26
6. Step 6: Final answer
   x = 890.38