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Finding the Fourth Proportional to 617.18, 851.81 and 420.75

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Solution

The fourth proportional to 617.18, 851.81 and 420.75 is: 580.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    617.18 : 851.81 = 420.75 : x
  2. Step 2: Convert to fraction form
    617.18/851.81 = 420.75/x
  3. Step 3: Cross multiply
    617.18x = 851.81 × 420.75
  4. Step 4: Simplify right side
    617.18x = 358,399.06
  5. Step 5: Solve for x
    x = 358,399.06/617.18
  6. Step 6: Final answer
    x = 580.70

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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.