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Finding the Fourth Proportional to 420.21, 579.87 and 245.54

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Solution

The fourth proportional to 420.21, 579.87 and 245.54 is: 338.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.21 : 579.87 = 245.54 : x
  2. Step 2: Convert to fraction form
    420.21/579.87 = 245.54/x
  3. Step 3: Cross multiply
    420.21x = 579.87 × 245.54
  4. Step 4: Simplify right side
    420.21x = 142,381.28
  5. Step 5: Solve for x
    x = 142,381.28/420.21
  6. Step 6: Final answer
    x = 338.83

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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.