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Finding the Fourth Proportional to 391.53, 540.28 and 216.87

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Solution

The fourth proportional to 391.53, 540.28 and 216.87 is: 299.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.53 : 540.28 = 216.87 : x
  2. Step 2: Convert to fraction form
    391.53/540.28 = 216.87/x
  3. Step 3: Cross multiply
    391.53x = 540.28 × 216.87
  4. Step 4: Simplify right side
    391.53x = 117,170.52
  5. Step 5: Solve for x
    x = 117,170.52/391.53
  6. Step 6: Final answer
    x = 299.26

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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.