Finding the Fourth Proportional to 1,111.21, 1,665.63 and 836.45

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.21 : 1,665.63 = 836.45 : x
2. Step 2: Convert to fraction form
   1,111.21/1,665.63 = 836.45/x
3. Step 3: Cross multiply
   1,111.21x = 1,665.63 × 836.45
4. Step 4: Simplify right side
   1,111.21x = 1,393,212.03
5. Step 5: Solve for x
   x = 1,393,212.03/1,111.21
6. Step 6: Final answer
   x = 1,253.78