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Finding the Fourth Proportional to 420.42, 629.71 and 214.63

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Solution

The fourth proportional to 420.42, 629.71 and 214.63 is: 321.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.42 : 629.71 = 214.63 : x
  2. Step 2: Convert to fraction form
    420.42/629.71 = 214.63/x
  3. Step 3: Cross multiply
    420.42x = 629.71 × 214.63
  4. Step 4: Simplify right side
    420.42x = 135,154.66
  5. Step 5: Solve for x
    x = 135,154.66/420.42
  6. Step 6: Final answer
    x = 321.48

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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.