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Finding the Fourth Proportional to 420.39, 629.37 and 266.49

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Solution

The fourth proportional to 420.39, 629.37 and 266.49 is: 398.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.39 : 629.37 = 266.49 : x
  2. Step 2: Convert to fraction form
    420.39/629.37 = 266.49/x
  3. Step 3: Cross multiply
    420.39x = 629.37 × 266.49
  4. Step 4: Simplify right side
    420.39x = 167,720.81
  5. Step 5: Solve for x
    x = 167,720.81/420.39
  6. Step 6: Final answer
    x = 398.96

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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.