Finding the Fourth Proportional to 1,019.12, 1,405.76 and 771.39

Step by Step Solution

1. Step 1: Write the proportion equation
   1,019.12 : 1,405.76 = 771.39 : x
2. Step 2: Convert to fraction form
   1,019.12/1,405.76 = 771.39/x
3. Step 3: Cross multiply
   1,019.12x = 1,405.76 × 771.39
4. Step 4: Simplify right side
   1,019.12x = 1,084,385.35
5. Step 5: Solve for x
   x = 1,084,385.35/1,019.12
6. Step 6: Final answer
   x = 1,064.05