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Finding the Fourth Proportional to 665.72, 998.58 and 421.73

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Solution

The fourth proportional to 665.72, 998.58 and 421.73 is: 632.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.72 : 998.58 = 421.73 : x
  2. Step 2: Convert to fraction form
    665.72/998.58 = 421.73/x
  3. Step 3: Cross multiply
    665.72x = 998.58 × 421.73
  4. Step 4: Simplify right side
    665.72x = 421,137.09
  5. Step 5: Solve for x
    x = 421,137.09/665.72
  6. Step 6: Final answer
    x = 632.60

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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.