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Finding the Fourth Proportional to 420.20, 579.80 and 254.42

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Solution

The fourth proportional to 420.20, 579.80 and 254.42 is: 351.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.20 : 579.80 = 254.42 : x
  2. Step 2: Convert to fraction form
    420.20/579.80 = 254.42/x
  3. Step 3: Cross multiply
    420.20x = 579.80 × 254.42
  4. Step 4: Simplify right side
    420.20x = 147,512.89
  5. Step 5: Solve for x
    x = 147,512.89/420.20
  6. Step 6: Final answer
    x = 351.06

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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.