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Finding the Fourth Proportional to 421.85, 631.76 and 329.78

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Solution

The fourth proportional to 421.85, 631.76 and 329.78 is: 493.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.85 : 631.76 = 329.78 : x
  2. Step 2: Convert to fraction form
    421.85/631.76 = 329.78/x
  3. Step 3: Cross multiply
    421.85x = 631.76 × 329.78
  4. Step 4: Simplify right side
    421.85x = 208,337.01
  5. Step 5: Solve for x
    x = 208,337.01/421.85
  6. Step 6: Final answer
    x = 493.87

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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.