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Finding the Fourth Proportional to 665.66, 918.66 and 489.17

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Solution

The fourth proportional to 665.66, 918.66 and 489.17 is: 675.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.66 : 918.66 = 489.17 : x
  2. Step 2: Convert to fraction form
    665.66/918.66 = 489.17/x
  3. Step 3: Cross multiply
    665.66x = 918.66 × 489.17
  4. Step 4: Simplify right side
    665.66x = 449,380.91
  5. Step 5: Solve for x
    x = 449,380.91/665.66
  6. Step 6: Final answer
    x = 675.09

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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.