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Finding the Fourth Proportional to 391.05, 539.61 and 216.38

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Solution

The fourth proportional to 391.05, 539.61 and 216.38 is: 298.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.05 : 539.61 = 216.38 : x
  2. Step 2: Convert to fraction form
    391.05/539.61 = 216.38/x
  3. Step 3: Cross multiply
    391.05x = 539.61 × 216.38
  4. Step 4: Simplify right side
    391.05x = 116,758.11
  5. Step 5: Solve for x
    x = 116,758.11/391.05
  6. Step 6: Final answer
    x = 298.58

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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.