Finding the Fourth Proportional to 1,061.80, 1,585.87 and 916

Step by Step Solution

1. Step 1: Write the proportion equation
   1,061.80 : 1,585.87 = 916 : x
2. Step 2: Convert to fraction form
   1,061.80/1,585.87 = 916/x
3. Step 3: Cross multiply
   1,061.80x = 1,585.87 × 916
4. Step 4: Simplify right side
   1,061.80x = 1,452,656.92
5. Step 5: Solve for x
   x = 1,452,656.92/1,061.80
6. Step 6: Final answer
   x = 1,368.11