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Finding the Fourth Proportional to 665.44, 996.72 and 421.54

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Solution

The fourth proportional to 665.44, 996.72 and 421.54 is: 631.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.44 : 996.72 = 421.54 : x
  2. Step 2: Convert to fraction form
    665.44/996.72 = 421.54/x
  3. Step 3: Cross multiply
    665.44x = 996.72 × 421.54
  4. Step 4: Simplify right side
    665.44x = 420,157.35
  5. Step 5: Solve for x
    x = 420,157.35/665.44
  6. Step 6: Final answer
    x = 631.40

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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.