Finding the Fourth Proportional to 1,103.51, 1,655.34 and 641.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,103.51 : 1,655.34 = 641.15 : x
2. Step 2: Convert to fraction form
   1,103.51/1,655.34 = 641.15/x
3. Step 3: Cross multiply
   1,103.51x = 1,655.34 × 641.15
4. Step 4: Simplify right side
   1,103.51x = 1,061,316.77
5. Step 5: Solve for x
   x = 1,061,316.77/1,103.51
6. Step 6: Final answer
   x = 961.77