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Finding the Fourth Proportional to 420.74, 631.36 and 266.45

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Solution

The fourth proportional to 420.74, 631.36 and 266.45 is: 399.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.74 : 631.36 = 266.45 : x
  2. Step 2: Convert to fraction form
    420.74/631.36 = 266.45/x
  3. Step 3: Cross multiply
    420.74x = 631.36 × 266.45
  4. Step 4: Simplify right side
    420.74x = 168,221.38
  5. Step 5: Solve for x
    x = 168,221.38/420.74
  6. Step 6: Final answer
    x = 399.83

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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.