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Finding the Fourth Proportional to 486.56, 671.88 and 312.20

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Solution

The fourth proportional to 486.56, 671.88 and 312.20 is: 431.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    486.56 : 671.88 = 312.20 : x
  2. Step 2: Convert to fraction form
    486.56/671.88 = 312.20/x
  3. Step 3: Cross multiply
    486.56x = 671.88 × 312.20
  4. Step 4: Simplify right side
    486.56x = 209,760.94
  5. Step 5: Solve for x
    x = 209,760.94/486.56
  6. Step 6: Final answer
    x = 431.11

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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.