Finding the Fourth Proportional to 1,290.78, 1,781.29 and 701.32

Step by Step Solution

1. Step 1: Write the proportion equation
   1,290.78 : 1,781.29 = 701.32 : x
2. Step 2: Convert to fraction form
   1,290.78/1,781.29 = 701.32/x
3. Step 3: Cross multiply
   1,290.78x = 1,781.29 × 701.32
4. Step 4: Simplify right side
   1,290.78x = 1,249,254.78
5. Step 5: Solve for x
   x = 1,249,254.78/1,290.78
6. Step 6: Final answer
   x = 967.83