Finding the Fourth Proportional to 1,385.40, 2,074.86 and 1,058.16

Step by Step Solution

1. Step 1: Write the proportion equation
   1,385.40 : 2,074.86 = 1,058.16 : x
2. Step 2: Convert to fraction form
   1,385.40/2,074.86 = 1,058.16/x
3. Step 3: Cross multiply
   1,385.40x = 2,074.86 × 1,058.16
4. Step 4: Simplify right side
   1,385.40x = 2,195,533.86
5. Step 5: Solve for x
   x = 2,195,533.86/1,385.40
6. Step 6: Final answer
   x = 1,584.77