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Finding the Fourth Proportional to 420.18, 630.14 and 214.86

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Solution

The fourth proportional to 420.18, 630.14 and 214.86 is: 322.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.18 : 630.14 = 214.86 : x
  2. Step 2: Convert to fraction form
    420.18/630.14 = 214.86/x
  3. Step 3: Cross multiply
    420.18x = 630.14 × 214.86
  4. Step 4: Simplify right side
    420.18x = 135,390.81
  5. Step 5: Solve for x
    x = 135,390.81/420.18
  6. Step 6: Final answer
    x = 322.22

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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.