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Finding the Fourth Proportional to 451.21, 621.81 and 311.07

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Solution

The fourth proportional to 451.21, 621.81 and 311.07 is: 428.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    451.21 : 621.81 = 311.07 : x
  2. Step 2: Convert to fraction form
    451.21/621.81 = 311.07/x
  3. Step 3: Cross multiply
    451.21x = 621.81 × 311.07
  4. Step 4: Simplify right side
    451.21x = 193,424.88
  5. Step 5: Solve for x
    x = 193,424.88/451.21
  6. Step 6: Final answer
    x = 428.68

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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.