Finding the Fourth Proportional to 1,088.81, 1,501.90 and 646.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,088.81 : 1,501.90 = 646.42 : x
2. Step 2: Convert to fraction form
   1,088.81/1,501.90 = 646.42/x
3. Step 3: Cross multiply
   1,088.81x = 1,501.90 × 646.42
4. Step 4: Simplify right side
   1,088.81x = 970,852.83
5. Step 5: Solve for x
   x = 970,852.83/1,088.81
6. Step 6: Final answer
   x = 891.66