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Finding the Fourth Proportional to 645.21, 890.40 and 350.49

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Solution

The fourth proportional to 645.21, 890.40 and 350.49 is: 483.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.21 : 890.40 = 350.49 : x
  2. Step 2: Convert to fraction form
    645.21/890.40 = 350.49/x
  3. Step 3: Cross multiply
    645.21x = 890.40 × 350.49
  4. Step 4: Simplify right side
    645.21x = 312,076.30
  5. Step 5: Solve for x
    x = 312,076.30/645.21
  6. Step 6: Final answer
    x = 483.68

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.