Finding the Fourth Proportional to 1,890.81, 2,834.18 and 915.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,890.81 : 2,834.18 = 915.57 : x
2. Step 2: Convert to fraction form
   1,890.81/2,834.18 = 915.57/x
3. Step 3: Cross multiply
   1,890.81x = 2,834.18 × 915.57
4. Step 4: Simplify right side
   1,890.81x = 2,594,885.60
5. Step 5: Solve for x
   x = 2,594,885.60/1,890.81
6. Step 6: Final answer
   x = 1,372.37