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Finding the Fourth Proportional to 420.34, 630.09 and 214.67

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Solution

The fourth proportional to 420.34, 630.09 and 214.67 is: 321.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.34 : 630.09 = 214.67 : x
  2. Step 2: Convert to fraction form
    420.34/630.09 = 214.67/x
  3. Step 3: Cross multiply
    420.34x = 630.09 × 214.67
  4. Step 4: Simplify right side
    420.34x = 135,261.42
  5. Step 5: Solve for x
    x = 135,261.42/420.34
  6. Step 6: Final answer
    x = 321.79

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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.