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Finding the Fourth Proportional to 420.54, 628.91 and 321.74

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Solution

The fourth proportional to 420.54, 628.91 and 321.74 is: 481.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.54 : 628.91 = 321.74 : x
  2. Step 2: Convert to fraction form
    420.54/628.91 = 321.74/x
  3. Step 3: Cross multiply
    420.54x = 628.91 × 321.74
  4. Step 4: Simplify right side
    420.54x = 202,345.52
  5. Step 5: Solve for x
    x = 202,345.52/420.54
  6. Step 6: Final answer
    x = 481.16

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.