Finding the Fourth Proportional to 1,059.60, 1,581.72 and 930

Step by Step Solution

1. Step 1: Write the proportion equation
   1,059.60 : 1,581.72 = 930 : x
2. Step 2: Convert to fraction form
   1,059.60/1,581.72 = 930/x
3. Step 3: Cross multiply
   1,059.60x = 1,581.72 × 930
4. Step 4: Simplify right side
   1,059.60x = 1,470,999.60
5. Step 5: Solve for x
   x = 1,470,999.60/1,059.60
6. Step 6: Final answer
   x = 1,388.26