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Finding the Fourth Proportional to 354.40, 489.15 and 221.68

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Solution

The fourth proportional to 354.40, 489.15 and 221.68 is: 305.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    354.40 : 489.15 = 221.68 : x
  2. Step 2: Convert to fraction form
    354.40/489.15 = 221.68/x
  3. Step 3: Cross multiply
    354.40x = 489.15 × 221.68
  4. Step 4: Simplify right side
    354.40x = 108,434.77
  5. Step 5: Solve for x
    x = 108,434.77/354.40
  6. Step 6: Final answer
    x = 305.97

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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.