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Finding the Fourth Proportional to 486.86, 671.80 and 287.70

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Solution

The fourth proportional to 486.86, 671.80 and 287.70 is: 396.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    486.86 : 671.80 = 287.70 : x
  2. Step 2: Convert to fraction form
    486.86/671.80 = 287.70/x
  3. Step 3: Cross multiply
    486.86x = 671.80 × 287.70
  4. Step 4: Simplify right side
    486.86x = 193,276.86
  5. Step 5: Solve for x
    x = 193,276.86/486.86
  6. Step 6: Final answer
    x = 396.99

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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.