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Finding the Fourth Proportional to 450.78, 620.91 and 420.54

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Solution

The fourth proportional to 450.78, 620.91 and 420.54 is: 579.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    450.78 : 620.91 = 420.54 : x
  2. Step 2: Convert to fraction form
    450.78/620.91 = 420.54/x
  3. Step 3: Cross multiply
    450.78x = 620.91 × 420.54
  4. Step 4: Simplify right side
    450.78x = 261,117.49
  5. Step 5: Solve for x
    x = 261,117.49/450.78
  6. Step 6: Final answer
    x = 579.26

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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.