Finding the Fourth Proportional to 1,019.67, 1,407.56 and 771.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,019.67 : 1,407.56 = 771.05 : x
2. Step 2: Convert to fraction form
   1,019.67/1,407.56 = 771.05/x
3. Step 3: Cross multiply
   1,019.67x = 1,407.56 × 771.05
4. Step 4: Simplify right side
   1,019.67x = 1,085,288.24
5. Step 5: Solve for x
   x = 1,085,288.24/1,019.67
6. Step 6: Final answer
   x = 1,064.35