Finding the Fourth Proportional to 1,111.07, 1,533.26 and 645.32

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.07 : 1,533.26 = 645.32 : x
2. Step 2: Convert to fraction form
   1,111.07/1,533.26 = 645.32/x
3. Step 3: Cross multiply
   1,111.07x = 1,533.26 × 645.32
4. Step 4: Simplify right side
   1,111.07x = 989,443.34
5. Step 5: Solve for x
   x = 989,443.34/1,111.07
6. Step 6: Final answer
   x = 890.53