Finding the Fourth Proportional to 915.60, 1,364.42 and 890.48

Step by Step Solution

1. Step 1: Write the proportion equation
   915.60 : 1,364.42 = 890.48 : x
2. Step 2: Convert to fraction form
   915.60/1,364.42 = 890.48/x
3. Step 3: Cross multiply
   915.60x = 1,364.42 × 890.48
4. Step 4: Simplify right side
   915.60x = 1,214,988.72
5. Step 5: Solve for x
   x = 1,214,988.72/915.60
6. Step 6: Final answer
   x = 1,326.99