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Finding the Fourth Proportional to 663.76, 996.45 and 421.30

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Solution

The fourth proportional to 663.76, 996.45 and 421.30 is: 632.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    663.76 : 996.45 = 421.30 : x
  2. Step 2: Convert to fraction form
    663.76/996.45 = 421.30/x
  3. Step 3: Cross multiply
    663.76x = 996.45 × 421.30
  4. Step 4: Simplify right side
    663.76x = 419,804.39
  5. Step 5: Solve for x
    x = 419,804.39/663.76
  6. Step 6: Final answer
    x = 632.46

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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.