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Finding the Fourth Proportional to 429.39, 591.69 and 311.15

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Solution

The fourth proportional to 429.39, 591.69 and 311.15 is: 428.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.39 : 591.69 = 311.15 : x
  2. Step 2: Convert to fraction form
    429.39/591.69 = 311.15/x
  3. Step 3: Cross multiply
    429.39x = 591.69 × 311.15
  4. Step 4: Simplify right side
    429.39x = 184,104.34
  5. Step 5: Solve for x
    x = 184,104.34/429.39
  6. Step 6: Final answer
    x = 428.76

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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.