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Finding the Fourth Proportional to 421.40, 632.64 and 397.64

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Solution

The fourth proportional to 421.40, 632.64 and 397.64 is: 596.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.40 : 632.64 = 397.64 : x
  2. Step 2: Convert to fraction form
    421.40/632.64 = 397.64/x
  3. Step 3: Cross multiply
    421.40x = 632.64 × 397.64
  4. Step 4: Simplify right side
    421.40x = 251,562.97
  5. Step 5: Solve for x
    x = 251,562.97/421.40
  6. Step 6: Final answer
    x = 596.97

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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.