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Finding the Fourth Proportional to 421.37, 581.33 and 311.11

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Solution

The fourth proportional to 421.37, 581.33 and 311.11 is: 429.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.37 : 581.33 = 311.11 : x
  2. Step 2: Convert to fraction form
    421.37/581.33 = 311.11/x
  3. Step 3: Cross multiply
    421.37x = 581.33 × 311.11
  4. Step 4: Simplify right side
    421.37x = 180,857.58
  5. Step 5: Solve for x
    x = 180,857.58/421.37
  6. Step 6: Final answer
    x = 429.21

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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.