Finding the Fourth Proportional to 1,388.08, 1,915.59 and 946.18

Step by Step Solution

1. Step 1: Write the proportion equation
   1,388.08 : 1,915.59 = 946.18 : x
2. Step 2: Convert to fraction form
   1,388.08/1,915.59 = 946.18/x
3. Step 3: Cross multiply
   1,388.08x = 1,915.59 × 946.18
4. Step 4: Simplify right side
   1,388.08x = 1,812,492.95
5. Step 5: Solve for x
   x = 1,812,492.95/1,388.08
6. Step 6: Final answer
   x = 1,305.76