Finding the Fourth Proportional to 1,070.78, 1,476.59 and 771.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,070.78 : 1,476.59 = 771.89 : x
2. Step 2: Convert to fraction form
   1,070.78/1,476.59 = 771.89/x
3. Step 3: Cross multiply
   1,070.78x = 1,476.59 × 771.89
4. Step 4: Simplify right side
   1,070.78x = 1,139,753.81
5. Step 5: Solve for x
   x = 1,139,753.81/1,070.78
6. Step 6: Final answer
   x = 1,064.42