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Finding the Fourth Proportional to 391.23, 539.88 and 216.56

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Solution

The fourth proportional to 391.23, 539.88 and 216.56 is: 298.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.23 : 539.88 = 216.56 : x
  2. Step 2: Convert to fraction form
    391.23/539.88 = 216.56/x
  3. Step 3: Cross multiply
    391.23x = 539.88 × 216.56
  4. Step 4: Simplify right side
    391.23x = 116,916.95
  5. Step 5: Solve for x
    x = 116,916.95/391.23
  6. Step 6: Final answer
    x = 298.84

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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.