Finding the Fourth Proportional to 1,298.58, 1,791.50 and 774.51

Step by Step Solution

1. Step 1: Write the proportion equation
   1,298.58 : 1,791.50 = 774.51 : x
2. Step 2: Convert to fraction form
   1,298.58/1,791.50 = 774.51/x
3. Step 3: Cross multiply
   1,298.58x = 1,791.50 × 774.51
4. Step 4: Simplify right side
   1,298.58x = 1,387,530.79
5. Step 5: Solve for x
   x = 1,387,530.79/1,298.58
6. Step 6: Final answer
   x = 1,068.50