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Finding the Fourth Proportional to 420.40, 630.52 and 189.20

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Solution

The fourth proportional to 420.40, 630.52 and 189.20 is: 283.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.40 : 630.52 = 189.20 : x
  2. Step 2: Convert to fraction form
    420.40/630.52 = 189.20/x
  3. Step 3: Cross multiply
    420.40x = 630.52 × 189.20
  4. Step 4: Simplify right side
    420.40x = 119,294.38
  5. Step 5: Solve for x
    x = 119,294.38/420.40
  6. Step 6: Final answer
    x = 283.76

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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.