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Finding the Fourth Proportional to 431.21, 645.93 and 321.63

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Solution

The fourth proportional to 431.21, 645.93 and 321.63 is: 481.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.21 : 645.93 = 321.63 : x
  2. Step 2: Convert to fraction form
    431.21/645.93 = 321.63/x
  3. Step 3: Cross multiply
    431.21x = 645.93 × 321.63
  4. Step 4: Simplify right side
    431.21x = 207,748.86
  5. Step 5: Solve for x
    x = 207,748.86/431.21
  6. Step 6: Final answer
    x = 481.79

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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.