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Finding the Fourth Proportional to 391.57, 540.28 and 225.78

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Solution

The fourth proportional to 391.57, 540.28 and 225.78 is: 311.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.57 : 540.28 = 225.78 : x
  2. Step 2: Convert to fraction form
    391.57/540.28 = 225.78/x
  3. Step 3: Cross multiply
    391.57x = 540.28 × 225.78
  4. Step 4: Simplify right side
    391.57x = 121,984.42
  5. Step 5: Solve for x
    x = 121,984.42/391.57
  6. Step 6: Final answer
    x = 311.53

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.