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Finding the Fourth Proportional to 421.05, 579.50 and 345.72

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Solution

The fourth proportional to 421.05, 579.50 and 345.72 is: 475.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.05 : 579.50 = 345.72 : x
  2. Step 2: Convert to fraction form
    421.05/579.50 = 345.72/x
  3. Step 3: Cross multiply
    421.05x = 579.50 × 345.72
  4. Step 4: Simplify right side
    421.05x = 200,344.74
  5. Step 5: Solve for x
    x = 200,344.74/421.05
  6. Step 6: Final answer
    x = 475.82

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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.