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Finding the Fourth Proportional to 617.80, 851.88 and 421.42

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Solution

The fourth proportional to 617.80, 851.88 and 421.42 is: 581.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    617.80 : 851.88 = 421.42 : x
  2. Step 2: Convert to fraction form
    617.80/851.88 = 421.42/x
  3. Step 3: Cross multiply
    617.80x = 851.88 × 421.42
  4. Step 4: Simplify right side
    617.80x = 358,999.27
  5. Step 5: Solve for x
    x = 358,999.27/617.80
  6. Step 6: Final answer
    x = 581.09

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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.