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Finding the Fourth Proportional to 420.38, 630.40 and 247.09

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Solution

The fourth proportional to 420.38, 630.40 and 247.09 is: 370.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.38 : 630.40 = 247.09 : x
  2. Step 2: Convert to fraction form
    420.38/630.40 = 247.09/x
  3. Step 3: Cross multiply
    420.38x = 630.40 × 247.09
  4. Step 4: Simplify right side
    420.38x = 155,762.38
  5. Step 5: Solve for x
    x = 155,762.38/420.38
  6. Step 6: Final answer
    x = 370.53

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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.