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Finding the Fourth Proportional to 486.68, 671.55 and 287.42

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Solution

The fourth proportional to 486.68, 671.55 and 287.42 is: 396.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    486.68 : 671.55 = 287.42 : x
  2. Step 2: Convert to fraction form
    486.68/671.55 = 287.42/x
  3. Step 3: Cross multiply
    486.68x = 671.55 × 287.42
  4. Step 4: Simplify right side
    486.68x = 193,016.90
  5. Step 5: Solve for x
    x = 193,016.90/486.68
  6. Step 6: Final answer
    x = 396.60

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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.