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Finding the Fourth Proportional to 421.21, 632.81 and 397.90

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Solution

The fourth proportional to 421.21, 632.81 and 397.90 is: 597.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.21 : 632.81 = 397.90 : x
  2. Step 2: Convert to fraction form
    421.21/632.81 = 397.90/x
  3. Step 3: Cross multiply
    421.21x = 632.81 × 397.90
  4. Step 4: Simplify right side
    421.21x = 251,794.65
  5. Step 5: Solve for x
    x = 251,794.65/421.21
  6. Step 6: Final answer
    x = 597.79

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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.