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Finding the Fourth Proportional to 420.79, 631.20 and 204.32

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Solution

The fourth proportional to 420.79, 631.20 and 204.32 is: 306.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.79 : 631.20 = 204.32 : x
  2. Step 2: Convert to fraction form
    420.79/631.20 = 204.32/x
  3. Step 3: Cross multiply
    420.79x = 631.20 × 204.32
  4. Step 4: Simplify right side
    420.79x = 128,966.78
  5. Step 5: Solve for x
    x = 128,966.78/420.79
  6. Step 6: Final answer
    x = 306.49

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Double scale
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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.