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Finding the Fourth Proportional to 489.70, 675.81 and 279.91

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Solution

The fourth proportional to 489.70, 675.81 and 279.91 is: 386.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    489.70 : 675.81 = 279.91 : x
  2. Step 2: Convert to fraction form
    489.70/675.81 = 279.91/x
  3. Step 3: Cross multiply
    489.70x = 675.81 × 279.91
  4. Step 4: Simplify right side
    489.70x = 189,165.98
  5. Step 5: Solve for x
    x = 189,165.98/489.70
  6. Step 6: Final answer
    x = 386.29

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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.