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Finding the Fourth Proportional to 391.47, 540.28 and 225.65

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Solution

The fourth proportional to 391.47, 540.28 and 225.65 is: 311.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.47 : 540.28 = 225.65 : x
  2. Step 2: Convert to fraction form
    391.47/540.28 = 225.65/x
  3. Step 3: Cross multiply
    391.47x = 540.28 × 225.65
  4. Step 4: Simplify right side
    391.47x = 121,914.18
  5. Step 5: Solve for x
    x = 121,914.18/391.47
  6. Step 6: Final answer
    x = 311.43

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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.