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Finding the Fourth Proportional to 486, 670.87 and 311.31

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Solution

The fourth proportional to 486, 670.87 and 311.31 is: 429.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    486 : 670.87 = 311.31 : x
  2. Step 2: Convert to fraction form
    486/670.87 = 311.31/x
  3. Step 3: Cross multiply
    486x = 670.87 × 311.31
  4. Step 4: Simplify right side
    486x = 208,848.54
  5. Step 5: Solve for x
    x = 208,848.54/486
  6. Step 6: Final answer
    x = 429.73

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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.