Finding the Fourth Proportional to 1,386.74, 1,911.93 and 1,135.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,386.74 : 1,911.93 = 1,135.10 : x
2. Step 2: Convert to fraction form
   1,386.74/1,911.93 = 1,135.10/x
3. Step 3: Cross multiply
   1,386.74x = 1,911.93 × 1,135.10
4. Step 4: Simplify right side
   1,386.74x = 2,170,231.74
5. Step 5: Solve for x
   x = 2,170,231.74/1,386.74
6. Step 6: Final answer
   x = 1,564.99