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Finding the Fourth Proportional to 421.14, 630.45 and 339.30

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Solution

The fourth proportional to 421.14, 630.45 and 339.30 is: 507.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.14 : 630.45 = 339.30 : x
  2. Step 2: Convert to fraction form
    421.14/630.45 = 339.30/x
  3. Step 3: Cross multiply
    421.14x = 630.45 × 339.30
  4. Step 4: Simplify right side
    421.14x = 213,911.69
  5. Step 5: Solve for x
    x = 213,911.69/421.14
  6. Step 6: Final answer
    x = 507.93

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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.