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Finding the Fourth Proportional to 486.37, 670.90 and 311.71

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Solution

The fourth proportional to 486.37, 670.90 and 311.71 is: 429.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    486.37 : 670.90 = 311.71 : x
  2. Step 2: Convert to fraction form
    486.37/670.90 = 311.71/x
  3. Step 3: Cross multiply
    486.37x = 670.90 × 311.71
  4. Step 4: Simplify right side
    486.37x = 209,126.24
  5. Step 5: Solve for x
    x = 209,126.24/486.37
  6. Step 6: Final answer
    x = 429.97

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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.