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Finding the Fourth Proportional to 420.14, 579.66 and 289.19

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Solution

The fourth proportional to 420.14, 579.66 and 289.19 is: 398.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.14 : 579.66 = 289.19 : x
  2. Step 2: Convert to fraction form
    420.14/579.66 = 289.19/x
  3. Step 3: Cross multiply
    420.14x = 579.66 × 289.19
  4. Step 4: Simplify right side
    420.14x = 167,628.98
  5. Step 5: Solve for x
    x = 167,628.98/420.14
  6. Step 6: Final answer
    x = 398.99

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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.