Finding the Fourth Proportional to 1,357.17, 1,873.53 and 915.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,357.17 : 1,873.53 = 915.78 : x
2. Step 2: Convert to fraction form
   1,357.17/1,873.53 = 915.78/x
3. Step 3: Cross multiply
   1,357.17x = 1,873.53 × 915.78
4. Step 4: Simplify right side
   1,357.17x = 1,715,741.30
5. Step 5: Solve for x
   x = 1,715,741.30/1,357.17
6. Step 6: Final answer
   x = 1,264.21