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Finding the Fourth Proportional to 486.74, 671.42 and 309.39

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Solution

The fourth proportional to 486.74, 671.42 and 309.39 is: 426.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    486.74 : 671.42 = 309.39 : x
  2. Step 2: Convert to fraction form
    486.74/671.42 = 309.39/x
  3. Step 3: Cross multiply
    486.74x = 671.42 × 309.39
  4. Step 4: Simplify right side
    486.74x = 207,731.41
  5. Step 5: Solve for x
    x = 207,731.41/486.74
  6. Step 6: Final answer
    x = 426.79

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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.