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Finding the Fourth Proportional to 421.84, 631.88 and 406.72

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Solution

The fourth proportional to 421.84, 631.88 and 406.72 is: 609.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.84 : 631.88 = 406.72 : x
  2. Step 2: Convert to fraction form
    421.84/631.88 = 406.72/x
  3. Step 3: Cross multiply
    421.84x = 631.88 × 406.72
  4. Step 4: Simplify right side
    421.84x = 256,993.04
  5. Step 5: Solve for x
    x = 256,993.04/421.84
  6. Step 6: Final answer
    x = 609.23

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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.